It's almost as if Warband had this exact same problem in the beta, and we got it fixed by raising skill requirements to ride horses, removing bolts/arrows from non-ranged classes between rounds, and adjusting proficiencies so that off-class weapons were not very effective. You don't see people running hybrid loadouts in Warband anymore. Yet here we are, 10 years later, repeating old mistakes. We have skill requirements on horses & ranged weapons in SP, they just need to be enabled for MP and skills for various classes need to be adjusted so that foot troops can't mount (heavy) horses and infantry/cavalry can't pick up bows.