Slitherine

Sword > Heavily shielded units

Spears > Horses

Arrows > Swords

Big Shields > Arrows

Horses > Arrows

2-Handed weapons > Big Shields, Swords, Spears

But what about AXE, HAMMER, CLUB?

If I can get an answer, maybe I'll write out a complete weapons FAQ. =)

I'm not sure. I always think of those weapons as general use in melee with no clear +/- factors. I think the one advantage to them is 1 hand vs 2 hand is a dilemma between shield protection vs extra damage output.
Most probably hammers and axes are better against heavy armor while swords and clubs are more efficient at wiping out light troops.