I don't think things need to be added, I think the way the game was designed made each class valuable in their own way. If you look at it as a team of three, Ra and Fo handle crowd control and keeping the Hu from being overrun where he can't attack, Hu finishes off major threat to Ra and Fo. Everything is locked down and stunned, getting killed fairly efficiently. Ra in the back will end up shooting traps that get stuck over the Hu. So it's all about how each one covers the other, they weren't supposed to be designed for handling everything on their own and if that happens there will obviously be one that handles it better. The one that handles stunning the entire group will be in the least amount of danger from being overrun.
Fear the fluff