Chewie's loyal friend ability not working right?

So I've been working on the cls rebel squad and having recently added c3p0 I've noticed something off about the squad's functionality. Chewie's loyal friend ability says it works on han solo and the weakest ally and as of now c3p0 is the weakest despite having recently finished his zeta skills and being gear 11 while everyone else is gear 12 or 13. So when I tried the rebel assault battle I noticed that loyal friend was working on cls instead of c3p0 even though cls is like 26000 atk whereas c3p0 is only like 22000 atk. What am I missing? And for future reference does it matter who gets the loyal friend boost? I was more concerned for c3p0 since he has no offensive skills in which to gain health steal or recover from damage like everyone else.