Has anyone effectively used the Death Knight as a warrior past the first act? I'm currently near the beginning of the second act with a warrior DK and he's just not cutting it on Tactical difficulty. He dies VERY quickly and goes through healing potions like crazy. The main problem I see with a DK warrior is the fact that his base armor class increases VERY slowly(starts at 5 armor, 12 armor at 11th level), heck my main character is a mage and has the same armor class as my warrior DK.
My current DK is level 11(+3Str, +1Agi, +1Con each level,) with his skill points split between his weapon skill and his armor skill, and a 18 armor rating(12 base, 6 from equipment), and is using a Two handed hammer which does 80+ damage for each hit.
Can anyone tell me what I'm doing wrong with my DK warrior? The only things I can think of doing to improve him is pumping his Con so he doesn't die as fast or giving him a one handed weapon and shield(but then it takes longer for him to damage enemies).