I consider militia spearmen to be little better than peasants. In fact, they are peasants except for one point of attack, a nice shield, and an unspecified "bonus vs. cavalry". What exactly is that bonus? +3 attack? Doubled attack? It matters.

Also, spear militia cost about 1/3 of your average mounted knight. Their hand spears shouldn't do anything special vs. a heavy charge, but with the bonus in mind, they should be able to inflict minimal to moderate casualties in the general melee. That is opposed to town militia, which do and probably should inflict minimal to no casualties. Professional spearmen should do serious damage to cav in a general melee, to the point of forcing late era knights to withdraw. Spearmen should not be able to resist any kind of heavy infantry, but even the cheap cheap pike milita unit can cause 30% casualties to dismounted knights using swordplay. That is quite effective from a logistical point of view.

Nothing from any era should stand against a frontal charge by knights except a braced pike formation. IMO knights, and cavalry in general, do and should dominate this game all the way up to pikes. And even then, there are ways for the canny cavalry commander to break up and defeat pike-based armies.