You have to look at the factions to see why the elite troops are mostly cavalry.
Aserai - like their predecessors, the sarranids, they are not well known for infantry
Battania - the 'forest rangers', their whole thing is ambushing from the trees, keeping out of melee when they can
Empire - specialization in armored cataphracts and skilled archers
Khuzait - horse archers is their entire thing
Sturgia - This is where there should be improved infantry units, i think most people were let down by how weak their infantry is
Vlandia - main tactics involve crossbows & heavy cavalry charge
So as you can see most factions tactics aren't really focused too much on infantry