As it is, by many a quirk and change, the current polearm weapons (excluding the double sided ones and lances for their unique properties) are as follows:
Spear - small - d6 - simple
Pike - large - d8 - simple
Halberd - large - d12 - martial
Naginata - large - d10 - cav/monk/exotic (can be 2h finessed)
Scythe - large - 2d4 - simple
Trident - large - d10 - martial
As is, there are 2 notable factors:
1) There is no medium polearm weapon for small races to 2h
2) There is weird distinctions between weapons.
In the former case, a simple or martial medium polearm weapon would be nice for small races to be able to 2h
In the latter case, normalization would be quite nice. Making the scythe medium for the former, pike d10 for being a simple weapon, and trident d12 to match halberd seems a potential, but this is just an off the cuff statement.
As is, the pike being d8 too kinda hurts to use it, for it being a simple weapon when most classes who would 2h a weapon would just go halberd for being d12, multiple damage types, and having its strong unique +4. Likewise the same can be said for trident as why would you want to use the trident over the halberd with the above?