A bow can't block, so the only recourse for an archer against cavalry charging in the open field is to do a jump out of the way, and shoot them as they run past if they didn't spear you out of the air while going by. Except now archers no longer get a chance to attack back. Cavalry can just spin and bump thrust while archer can do....nothing. Pull out a 6 inch hammer and block all day? You don't have time to jump, land, draw an arrow and shoot before you are bump slashed repeatedly.
Awesome job. It sure was terrible that an archer on foot could attack a horseman in 1vs1.