Fire Emblem is a difficult series, I don't know if you guys have heard

[Words Of Wisdom]

Khuutra said:
My main point here is that Rath is highly mobile, and that seems important for HHM.

Rath can have the best stats of all the archers and high movement but you get him relatively late in the game.  If you want to spend the time to level him up then you won't be disappointed.