[@duskshine749] - No worries, take your time.
Excellent question though. If you've briefed and gleaned over the characters thus far [those that remain, anyways] some of the Aeons seem destined to the specific character in mind with a certain trait that alludes to a personality of some kind or a hidden strength. I think it's something we've all naturally picked up on and decided that Aeons were pre-determined and selected for particular SOLDIERS. But, you're free to approach this manner in any way you deem fit.