I doubt they're fake; that sure looks like land units fighting on a blue field, to me. The models wouldn't be that hard to make; the ship would be a mount model, like the chariot, and the soldiers part of the "crew." But the unit would travel on land, and other problems arise, so it wouldn't be able to be in the campaign without some MAJOR fudging. I think it isn't worth the trouble, but others might have a different opinion.