Keep Drive Core or Give it to Morda

Not, its not. The premise of your argument rests on the idea that the presence of the core will improve Nexus's defences. This isn't even put forward by anyone in the game, it's just you, so it's up to you to explain how that will result in the timeframe you've set. Clearly having the Krogan on-side will help massively against the Kett in the long run, so logically you're arguing this based on the short term.



It's already been pointed out why Morda needs power, ultimately for the same reasons Las Vegas needs it. Suggestions about how they can simply make do with solar panels/happy thoughts/something else miss the point that on a planet full of psychopaths and sandworms, having your power needs being satisfied by a ready-made and defensible unit will save a lot of time and resources and will ultimately allow the colony to grow at a faster rate.

The argument about what the Nexus 'NEEDS' isn't in favour of keeping the core, as there are no apparent power crises thanks to the moored Arks and you know that the Nexus primarily needs raw materials and support because that's what the leadership tells you it needs. There is no indication the Nexus is still capable of jumping to FTL, either. It's a half-built space station.

Keeping the core is not a rational decision. At best, it's knee-jerk. Your job as pathfinder is to settle Heleus and you're not accomplishing that by hanging onto a relic on the off-chance you might figure out a use for it later.