The problem with adding more weapons is knowing where to stop. It makes sense to introduce things like nunchaku and kama for use as regular farm implements as well as weapons, and one could easily argue for breaking the existing short/long/scimitars/two-handed swords into something more diverse, to include rapiers, claymores, katanas, etc. But not every player would appreciate reflecting every type of Earth weapon in the game: Setting a uniform is exacting enough without having to first stop, head to Wikipedia, and consider whether your squad would be better off with ghurkas or mambeles. (Or billhooks, or Lucerne hammers, or bec de corbins, etc . . . )
What I'd like to see:
1) More meaningful variation (things like acknowledging that some wooden weapons can actually be quite effective, allowing players a greater latitude in equipping troops without functionally crippling them),
2) More cultural variation (if players embark in a land of pandas, bamboo, and elephants, trying to force the game into an atmosphere of medieval European fantasy is already a lost cause), and
3) More means of use. If dwarves have axes, why not throwing axes? If their weapon gets stuck in someone's wound, why don't they grab a weapon from the nearest corpse?