Ark and Nexus constructed too fast?

Isn't it even stranger that the Nexus basically has to be expanded roughly 60% (adding the Stanford Torus wheel and another Pylon) in the Andromeda galaxy? At least in the Milky Way you could somewhat explain the fast construction by having access to a galaxy-wide industrial base. In Andromeda the rest of it is completed by a population 1/3 the size of Iceland in a galaxy without any established industrial base whatsoever. ;-)

Well...

Speaking like a Sci-fi nerd, I believe the time difference between building war ships and bottle ships has to do with the complexity of the materials and defences used in construction.

The thing is, a dreadnought has much more armor than an Ark not to mention GARDIAN systems and shields strong enough to withstand direct fire from the main canon of other dreadnoughts.

As big as the Arks are and as complex as their propulsion systems look, they are a stretched thin can compared to the dreadnoughts. Therefore is not unfeasible to complete them under 10 years.

Furthermore, each species was building it's own separate Ark simultaneously so their individual manufacturing capabilities were not as hardly pressed as undertaking such endeavour suggests.

The Nexus is way bigger and more complex than the arks but if the manufacturing capabilities of several species was combined over a period of one or two decades it's not unfeasible. I still don't believe it's heavily armed, armored and shielded, at least not before it reaches Andromeda and beggins upgrading itself.

Combined on Reaper War level? Sure, if they made 10km Crucible in less than a year, making 15km Nexus in 10 years would be piece of cake. To the point that biggest project in this Cycle's history was "for fun" project of some "benefactors".
I actually now understand why economy was crumbling in 2185. It was just a massive unemployment hit from these Nexus builders.

Because we've been building skyscrapers for near damn a century. It's well-established technology, not bleeding edge like the Ai's tech.

The engines and maybe even the cryo pods may be bleeding edge technology, but besides that they're just large spaceships/stations. Humanity has been building habitats in space for decades, the other species even longer.

No, you're right, but there is a first for everything isn't there? The engines are indeed special in that they use the static buildup for power instead of needing frequent visits to planets to discharge. Has it been established that FTL travel is otherwise destructive to spacecraft? Clearly they brought enough fuel, the ships must be big for a reason.

The whole issue of this supposed impossibility of constructing these ships in the time available has been done to death in innumerable threads here since this site opened up and for several months prior to that on the old BSN... it's a broken record at this point and certainly not worth starting another new thread to rehash the same old issue over and over and over again.  Your post contains a grand canyon wide hole in your argument.

OP - if they can build the 14 km long crucible in 6 months, they can certainly build the ships involved in the AI (including the Nexus) over a 10-year period.  Construction times are something that is greatly variable from project to project.

Fortunately my suspension of disbelief is working so, no, doesn't bother me at all.