I agree with Strew. Not sure he is too overpriced, really, but if Chakax is doing what he is supposed to be doing, which is guarding a Slann in a TG unit, that unit is incredibly expensive. Of course, it's also a tough nut to crack at that point, so the points are protected fairly well. What sucks is when the unit gets charged (as Strew said, M4 just doesn't let you get the charge off) by something like a Chaos Lord on Chaos Dragon with 11 attacks, even Chakax might not survive that. And he has to challenge.
As for named characters, it depends on your local meta-game. It's common practice around here for "friendly" games to have named characters, which I hate.