well again, you could have them 3 characters like this (i missed a few things i know. hey i've been up for 32 hours)
vegeta - ssj1, ussj1, ssj2 (which is pretty much majin vegeta so lets called it ssj2)
piccilo - fuse with nail, fuse with kami, super namek
gohan - ssj1, ssj2, mystic gohan...