problem is, there were no medieval swordsman units, with exception to spanish rodeleros which had very limited use. distinction between spearmen and pikemen is more social than technological. spearmen were tribal militias, their formation was divided in groups belonging to different clans consisting the tribe. or it was a feudal levy, a disorganized mass of armed men. while pikemen were drilled troops, what allowed them to use a tight enough formation to use such an unwieldy weapon as pike effectively. men at arms were simply knights on wage, when kingdoms matured enough to pay for their armies with money. they were mounted troops not foot soldiers. they fought on feet sometimes but just like knights.