The best replacement for polearm is greatsword aion.

The best alternatives to polearm are rated as following:
★★★★★  greatsword aion
★★★★★  spear
★★★★  greatsword
★★★★  staff feral druid
★★★  spear maplestory
★★  dual wield
★★  spear dk
★★  greatsword gladiator
★  spear diablo 2
★  ivandis flail
  2h axe

Your alternative for polearm is not listed? Suggest!
Speaking about polearm, one probably shouldn't forget about paladin.

Other search terms related to polearm and their ratings are:
★★★★★ paladin
★ dk tank
You have in mind a companion for polearm and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of polearm in all years. Click on graph for more.
polearm
greatsword aion
spear