I'd form a nice line of infantry, spear in front, sword behind and a 2 or 3 units of archers in skirmisher mode in front and the rest at the back.

Cavalry on flanks, general behind the line.

Send out your most expendable mounted seargants and micromanaged them so they kill off any units the AI abandons or any archers he sends forward. The byzantine cavalry will be on skirmisher mode and not want to engage your Mseargants and will run away in relation to their general and the position of your MS's general. So you may be able to scare them away fr omthe byzantine army and chase them into the edge of the map and charge into them like that.

Ignore the naptha throwers and ballistas, march your line forward, stop some distance fro mthem and then charge your heavy infantry into the enemy's infanty, through your spearmen. Take your spears and charge them around the flanks and trap the cavalry and charge into their rear with your feudal knights, who should be some distance away from the line and charging round the rear at the same time your infantry engages, ready to do a proper micromanaged charge with hold formation. Charge your units of feudal knights one at a time so you can counter any odd unit which decides to charge into your occupied knights.