Originally Posted by Lied

I'm at a point where almost all of my 3 star units have all their equipment slots unlocked and the ones who can be skilled up with 2 star units are already max skilled, so when I get a copy of a max skilled/max slotted 3 star I've just been feeding it up to level 7 then using it as exp fodder or just selling it. Is it worth keeping more than one copy of a 3 star unit? I'm assuming no, but wanted to double check in case I've been throwing the extras away when I shouldn't be.

Kind of, some people go full OCD on making single type raid teams (there's 6 slots for a reason).
I'm doing something similar, doubling up on the 3* once I maxed one, I've more gold than I know what to do with anyways. It's good to have them (especially the slower characters as I found out too late T.T) since there are missions where you want a slower speed and shit.