That's what makes the game so awesome I do enjoy playing as Agitha though because sometimes she amazes me. When I was forced to play as her, I expected to lose. But to my surprise she killed the map hahahahaha! I also feel bad for Volga and Zant. Being killed by a girl with a parasolOMG NESSA YOU SWORE!!!!!!!!!!
But yeah it seems like you have the captain kills, the boss downers (some seem to be better on some bosses) the all rounders (Link and volga primarily) and the mook slayers such as agitha.
It saddens me that aside from a few not all of the characters are equal to each other.