Hugo is harder to bring down that Zangief is, in my view.
Dont know about King, tho. Hes got way more variable moves and power than those two: Submitions mat, brawl, agility, piledrivers, power wrestling, high flying moves, you name it.
They are probably stronger raw wise, i give them that, but they are slower than King is and way more limited. Besides, its not like King never beat anyone on Zan`s size anyway.
King can't beat either... the guy's got great technical skill, but nowhere near the strength or the size nessisary to fend them off... plus I'm not even sure he could lift these guys. nor can he match the feats that Zang has accomplished (King menttioned the F5 Tornado feat, and the Bear Wrestling for fun feat.)
King's got speed, agility and technical skill over them, but in terms of raw power, durability, and execution of the moves. Zang nd the fake Andore Jr have it in spades.