Desert Raiders historically don't fare too well up against either Lombos or javelin throwers. As the Desert Raiders do have that range tag, you're going to be able to do a good amount of bonus damage to them.

Varangians have an additional +1 melee armor, so they aren't going to be taking nearly as much damage from the Ghulam as other arms would be. And the Ghulam's double hit comes off twice, so the Varangian Guard is a pretty clever response.

When facing aggression as Byzantine, consider stopping at Cistern level three instead of five. Pull villagers off stone to get units out sooner, because going for level five can delay your military and berry access.

Against Ghulam rushes, Byzantine needs multiple towers with arrow slits to shoot down the heavily armored Ghulams.

Limitanei are a safe answer to many things, but if the Ayyubid goes for Ghulams, suddenly the Limitanei can't do much damage because of the Ghulams' heavy armor.