With Shogun 2 are focus on battles is definitely making sure they play smoothly and with all systems working properly.

Whilst the matched anims are only 1v1, the combat calculations are not. The game knows how many attackers are available when a man makes an attack and if there are multiple attackers the kill chance is greatly increased. So the anim may be 1v1, but the combat system is not.

Yari Cav are going to be the anti-cav cavalry, and different cavalry units will vary in their effectiveness against non-spear infantry.