issues with warwicks kit

i feel that warwick isnt especially unballanced as he is, however his passive (which triples when he is below 20% hp) makes the early trades nigh impossible to win, he falls off more and more during lategame, but with his duelling power in early game so powerfull he shuts down the enemy team so effectively there usually is no lategame, or he is so fed when at lategame its impossible to stand against him.

i think tuning his passive down a bit would be an effective way to balance him out for the rest of the game.

any thoughts?