That can barely count, they just killed him so he couldn't make another controller and put them back to sleep as he threatened to do. #16 technically fought on the side of good, as the only person he fought was Cell three times.
Anyway, in the History of Trunks they fought together, but in the series they went around with #16 and although they didn't all fight at one time, they went around as a group. #16 has some really nice attacks and he's been suggested before, i'm sure people would love to see him in.