[FarAway Pretender]

While it might be interesting and realistic to do this sort of thing, at the end of the day, I'm not sure that you've really improved the playing experience, except for the detail nuts who want a game even more detail-oriented than Dom2 already is (I consider myself such a nut, but don't think most folks love that sort of thing). Given how chaotic the battles already are, it'd just be one more level of complexity/randomness that I could only exploit in a handful of situations, and would be utterly frustrating in others.

Technically, you'd only want a Pike to get an AP bonus against charging cavalry--the long L already makes your cavalry do a morale check when trying to attack, and unless I'm missing something, a pike isn't any more dangerous against a stationary knight than a spear would be.