You see he needs bonus AD pretty badly (Passive and ultimate both scale with bonus AD) . Yeah there's a thing with R + S combo (Bonus HP and bonus AD) and yet he has such a low attack speed so he basically can't even apply stacks in battle. We can go for Resolve + Precision tree but there will be no bonus AD at all. How about to give at least a little bit increased attack speed growth per level? 1% per lvl is just too depressing.
AD is not really that ideal for him. He naturally had good early game damage, but it all falls off later on in the late game. In teamfights, You want to build Cleaver to help shred armor, and tanky stats so he can survive long enough to do all of that. It's not the most damage dealt by your team, but you make it so your AD champs will maximize their damage, while still applies a lot of bleeds yourself.
He's meant to be an off-tank, which does like resolve. You're likely trying to play him as a primary source of damage, which he simply is not (unless he gets super fed).
