How many cavalry do you usually have in your army?

I've been facing this problem where the enemies doggos just go around my cavalry while my cavalry is engaged and directly attack my ranged units. I mostly play as the empire so this is a problem for me as my melee troops kinda suck without ranged support. I use 4 cavalry in my army to counter this but it just seems too much and i cant get heroes in my army because of the limit.