Ok here are units you should use for atacking an enemy and defending your town:

Attacking:
Make Alot Of scouts and camels they are cheap but strong and also make spermen and archers and don't forget siege weapons make alot of battering rams and put your infantry insidem so when a batering ram is destroyed soldiers burst out and attack it is soooo cool!

Defending:
to defend your town buld 4tours together so they form a square its really strong and make skirmishers knights pikemen and 30 monks they convert the enemie soldiers so they don't have a chance.