I had a similar experience when I tried the rebellion with an only partially trained Aria but I didn't play it for long enough after that to really know whether there were some events she'd fail eventually. Probably should read Ideal rather than Great since you don't have to have all of that stuff maxed out on her. It takes quite awhile to build support with the rebels and you're going to want to spend some time training up a seriously strong combat team anyway though so you might as well pick her up early and get her trained up as much as possible before you start the final stages of the rebellion.Just some words about Aria stats as Chancellor. Per wiki
I must say that This seems to me a bit of an overstatement. Sure, if Aria have all of this, she will be a mix of Caesar Augustus, Bismarck, Lincoln, Kemal Ataturk and Churchill (but with tits). But you don´t need this to make of her a pretty decent Chancellor.
In my run, she is not workalcoholic, she is not perfectionist, her intelligence it´s above 60 but below 90 and her Admin it´s 38, and so far all the Chancellor events (but one?) have gone quite right. Things seem to run quite decently for the new republic with a suboptimal Aria.
I imagine there is some mix of stats/skills/traits that would serve as sort of a "minimum viable" threshold for her to be decent as a leader but I don't know what those might be. Is it a sliding scale for each or is it all or nothing? Do you get a boost at 90 for each stat while 89 is the same as zero? Or does 75 give you a partial bonus but not the full bonus? No idea. Some of the stats in this game are definitely all or nothing but not all of them.