Suggestions - make pikemen / spearmen immune to cavalry flanking and mounted charge abilities, and to some beast special attacks

It'd be nice if pikemen had some defensive capability against mounted troops and beasts as well as their special attacks - say a bonus to defence against cavalry unless getting attacked from behind, being immune to the mounted 'Flanking' special attack, and to 'Mounted Charge' (again). I know it's a fantasy game, but this would make them seem more like real medieval pikemen actually were and make it seem more authentic. It'd also make them a more useful unit. Currently they just become obsolete later in the game.