Varangians have caused me fits, but as has been said - their numbers are finite. Just mass arbalester fire on them to kill them as quickly as possible. Remember you can afford to lose a wave of troops, even some battles to thin their numbers. Arbalests and CS etc are two a penny & often are ransomed back after the battle. VG are rare and the arbalester bolt takes no prisoners.

Kats are rather less daunting. They do not stack up very well against Chivalric Sergeants, but your spears will be very vulnerable to Biz foot and you'll need a good general to bolster morale. Halberdiers are pretty solid units against heavy cav and are not so vulnerale to swords. You need AP stuff to kill kats reliably and your standard army appears to have none.

Your CMAA swords should be able to beat Biz infantry one on one, even on expert. The problem is the 100 to 60 quantitative edge. Make sure they are in a thin, eg double, line so that you are not enveloped and try to flank them with your knights.