Quote Originally Posted by lilljonas
No, armour and weapons are completely separate. They don't affect each others, so getting an armourer won't affect the weapon upgrades and getting a weaponsmith won't affect the armour upgrades.
Which is very useful if you are building a desert army. If I am the Spanish for example have at least one of the iron containing provinces with maximum weapons bonus and no armour. You can then make awesome units which dont tire fast in the desert.