Eh...Why would your "friends" (NPC's) let you choose their clothes?
Squadron, of course. You are their superior in a stand-alone military cell, you have the right to choose their uniforms. But NPC's?!
Also, the likes of Y'shtola have unique abilities that no one else does. They will probably have them in the trust system as well, to a point. For example Alphinaud with his special Carbuncle. It would not work with squads.
Then there's also the fact that squads level up...NPC's won't most likely. They will have whatever stats are necessary for given content. They will also be programmed to do their job, not be given commands by you. Just like the guys in Scholars quest line. You do give commands to your squadron however because...you are their superior.
These are two different system for a good reason and I don't want them to become one and the same. It would ruin both of them because compromises would need to be made.