Unit matchups

[Kjeld]

Unless specified, I don't think there is any hardcoded benefit for a weapon or weapon type against particular enemies.
AFAIK, only the properties of the weapons matter (ie : damage, attack, defense, range, and misc. specials like morningstar's shield bypassing ability, poison ...).
Unless I am mistaken, pikes are useful against charging cavalry, because you can repel the lance attack (pikes and long spears are longer), but that's it.