I am also currently struggling to learn how to win these battles. Have had a real hard time winning even the middle amount battle. Ok, well, not REALLY hard, but harder than I thought it would be. I am usually fairly set to Battle by myself, instead of Auto, I get it, but these troops don't seem to follow a pattern. I'm sure they do, and I see the given info, like with all troops in the game. But, it really is a challenge.
This is my first time thru Egypt, I have done Japan and Vikings once each. This is the first time I have actually been stopped up for a day because there was one mid-level battle I just could NOT win. Finally, I got smart, and hit the dismiss button. I had to wait out the timer still, but at least it presented me with a new challenge, rather than fighting the same battle over and over, and won that one first try. So, maybe that one had me Battle-shy, but it just wasn't logically working out at all... Keep at it!