yeah, you really just need the experience with the class. imo, you would probably need low-rate experience before trying them on a high rate/olympiad to be good at it. if you have good gear, dwarves are a pain in the ass for my pw, atleast in the oly.. and if they have a bow that just screws me over even more. luckily, i dont recall a dwarf beating me though, lol. their stun lands all the time though, and when enchanted even more. so i guess if you want to be cheap about it, just stun everyone to death.. you still would win. against mages though, no idea how a dwarf could win unless they dont try to slow you (slow, mass slow, frost bolt) or kite you with nukes.
gl.