Mass Effect has no plot holes

1. The place where anderson unlock the normandy and the room with the death asari where saren took control of the citadel arm are different places.
I doubt that gaining access to the citadel arm can be done in the same place, from the same console, with the same security measures and with the same ease as unlocking a ship (which can be done even from udina console!)

2. as I've said, even if Saren had managed to sneak in the CC and to open up the arms the same way anderson did, he would still have to go to the tower and trasfer control of the citadel to sovereing. How can you do that without a small army? You can't.

Couldn't Saren have passed control of the Citadel to Sovereign before going to Eden Prime? At that time, he was still a Spectre who, most likely, could go anywhere on the Citadel without any suspicion. Once he's at the controls, he lets Sovereign know. Sovereign shows up, gets a hold of the tower, and hello reaper invasion.

but after that Saren must transfer the control of the citadel to sovereing.
and that could be done only from the tower panel.

If saren failed to do so quickly (fighting is way alone of with few allies from the CC room to the tower), the citadel defence force would regain control of the arms before he transfer control to sovereing, re-open it, all the fleets in the galaxy arrive and the sovering is done.

That, however, still begs the question then of Why did Saren, Sovereign's ally, believe that finding the Conduit was any advantage to him when the problem as Sovereign already knew it was getting someone to turn on a console on the Citadel. A simpler solution would have been to just indoctrinate someone who worked there.

STILL, the plot hole exists BECAUSE Bioware provided no explanation within the narrative itself.  We are, therefore, compelled to construct these complex scenarios on our own to fill in the plot hole that exists... and most of us have been doing that ever since the games came out.

Why would he be fighting anyone if he's able to get to the panel without any suspicion? Once he alerts Sovereign that he's at the panel, Sovereign shows up. The Citadel fleets won't be expecting Sovereign. Sovereign can take care of them easily before attaching itself to the tower. As far as all the fleets of the galaxy showing up? No. The only reason why the Alliance showed up when they did is because they were already on alert. Fleets from the other species never showed up. By the time anyone does show up, the reaper invasion would have started

The inconsistency in the narrative is that we are told outright he "thinks like a machine."

Again, it does not need to know why it doesn't get through.  The first test is putting an alternate signal through and does the console itself still work.  Since it would, the "why" the keeper one didn't becomes irrelevant. 

Sovereign also does not need to show himself to have a "non-keeper" mook try to activate the console.  The process we're given in the narrative is that the keepers activate the console without Sovereign having to show himself.  It is not activated by Sovereign personally and, in the end, we are shown that the console is accessible by anyone who can access the council chambers.  One person who can get there who will "listen" to Sovereign's signal is sufficient according to the narrative we're given.  Inconsistent with the narrative is that Saren has to open the arms to allow Sovereign to sit on his perch and be shot at by the Alliance.

we have to assume an intolerable level of incompetence here... I mean, imagine a top CIA field agent enter whereven the United States manage their anti-missile shield or some other fundamental defensive system (like the citadel arms, not the useless lock/unlock-ships-to-the-docks system...) without specific authorization.

let's say that he succeeds. He is inside.

Than what? He start hacking things and messing with the panels? log in to the computers? Nobody would stop him? Nobody controls what he is doing?
Hey boys do not pay attention to me, just have to do something very important for the president, spectre business you know... can I use that panel overthere? yes, the most important one.
Yes mr Saren, of course, no problem
Thanks. Almost finished.... give me another minute... and... done! Thanks!

After that, Sovereing appears. Ships start to explode in the sky. Tha arms of the citadel start to close. How would people in the CC react? (assuming that they were so incompetent and dull to allow Saren to mess with the panels)? By shooting Saren
And saren need to go from the citadel control to tower to transfer control of the station to sovereing (Vigil exact quote).

Sovereing didnt' attack immediately, if you notice. It waited until the geth weakend the citadel fleet and saren was in the tower.
Sovreing want to be sure that:
a. the arms of the citadel stay closed (and so be protected from the inevitable counterattack... the other fleets proved to be quite slow to react, true, but what if they weren't? Would sovereing risk everything betting on the slowness of asari and turian? That would be lazy)
b. get control of the citadel in little time (if saren and it's minions are overwhelmed, who is going to transfer control to sovereing? Who could keep the arms closed? What if the asari/turian fleet start to arrive?)

Every scenario where Saren is alone (or almost alone) and must fight his way to the tower is incredibly risky for sovereing.

The only one constructing a "what if" scenario is you, as in "what if everything in the ME universe we don't have explicit information about works exactly like I think it should",

I am just saying if x and y happened before the start of ME1, the plot makes sense. That's not "what if" that's deduction from that fact that are established in the game. Did it absolutely have to be that way? No, but it absolutely can be this way and then it does make sense.

And not taking organic by surprise, beheading the council and not shoting down the mass relay network, ultimately caused their defeat.
So Sovereign was right to try to make the invasion start as usual.
In retrospect, it could have just flown out to darkspace, yes. The invasion would have probably been more effective.

So, we can say that it was probably a strategic error. An evaluation mistake.

But if you create a villain that is (a lot) more powerful than the good ones, well, the only way to make the good ones prevail is to make the villain make some small mistake. If the powerful villain performs his plan perfectly, with zero errors and missteps, the good ones are doomed, even if they fight bravely and cleverly.

I don't think that reapers making some evaluation mistake here and there is a plot hole.
they are not deities, even if they seem to believe it and would like to make everybody believe it...


I also personally believe (but that's headcanon) that the reapers are not as powerful as they say they are.
To arrive from deep space, to waste resources in the process, to fight system by system, having to attack the major planets and the citadel without a surprise effect, to suffer greater losses than usual.. it was not a good thing for them.
Yes, of course they still have the upperhand, but they are weakened.
They failed to completely eradicate the prothean, and that made the next cycle much more complicated to defeat.
And a much more complicated cycle to defeat can be a much more difficult cycle to eradicate.
The crucible is the last straw. They are done.

So the success of the sovereign plan was important.
A non-conventional invasion was something to avoid, if possible.

But they would have won anyway, had it not been for shepard...

I always took the 'conventional' invasion by the Reapers as an act of urgency.

By the end of ME2, remnants of Reaper technology (bits of Sovereign, Collector technology, the Reaper IFF) were in the hands of the Organics. It would have been likely that the races of the galaxy could eventually develop advanced weaponry/technology from these captured items and eventually gain the capability of actually meeting and effectively countering a Reaper invasion.

Knowing the Reapers, they most probably knew this was a likelyhood and came in 'the long way' from Dark Space to snuff out the galaxy while they could still do it easily.

That's my own spin on things. Whether or not this is a feasible explanation is up to much more knowledgeable folks.

Sorry if my ast post came off as a bit hostile, upon re-reading it, I guess it might have. here is what I meant to say:

"what if" and just "if" are not the same thing.

One is based on observations With just "if" you make an assumption based on observation. For example, I observed in game that Sovereign didn't go directly for the Citadel, so I am assuming that it would have been to dangerous for him to do so. There is no what in there. I am not asking the question "what if Sovereign had done this or that instead of what is in the game." I am just saying "if Sovereign didn't see a good chance to succeed by sending a small contingent or going himself just like that, than what we've seen makes sense".

Unless you can give me a good reason as to why my - admittedly made up - reason for why the plot CAN work is invalid (a reason that goes beyond "I don't think Sovereign would think that way"), I don't consider there to be a plot hole.

Maybe we just have a different definition of a plot hole. You need for every detail to be explicitly told in the plot, I am ok with implications as long as there are not direct self-contradictions.

Of course, where do the self-contradictions start? That's a tricky issue. For example, here is something that IMO borderlines on a plot hole: In the game, it is mentioned multiple times that the reapers are very careful to wipe out tech remaining of the protheans. Obviously, they don't catch everything, so things like the Eden Prime beacon were missed. Given the size of the galaxy, that is feasible to me. However, what really stretches suspension of disbelief IMO is the fact that the reapers apparently just left the conduit relay standing in the presidium. Given that this was the protheans first attempt at building their own Mass Relay and given that the reapers are the absolute masters of this technology, I have a hard time seeing how they could just have missed it or ignored it when they took over the Citadel during the prothean cycle invasion.
IMO, that stands in contrast to the things we learn about the reapers in the game. Is it a plot hole? Not sure, the reapers might still have missed it or might have trusted in the keepers to remove it eventually, so it's not like there couldn't be an explanation but IMO here, the contradiction between what we learn about how things work in the ME universe and what we see in this particular case is rather severe. Since there are possible explanations, it may not be a plot hole either but it isn't great writing.
For that matter, I also don't think the fact that Sovereign's reason for not going for the Citadel right away is not put into explicit words in the game is not great writing either. Main difference I see is that there is also nothing explicit in the game that prevents Sovereign from taking the cautious course that he did.

Ultimately, it's all a question of how believable different people think different scenarios are. I tend to be on the lenient side and I try to make plots work in my mind rather than trying to contradict them. I get that others (like you or e.g. smudboy if anyone remembers him) have different definitions and sensibilities, i just never found it fun or productive to come up with reasons why something doesn't work, rather than for reasons why something works.

Is it a plot hole that the catalyst didn't know about the protheans altering the signal to the keepers even though the thing says its part of the Citadel? Or that it didn't know the portheans built a mini-me relay on the Citadel before the harvest started? Or is it because the thing never existed until the last 10 minutes of a trilogy?