I don't know if it's because it was a city battle, but he didn't won thanks to the capture point. Yet he only has the option to "end the battle", and not "continue the battle".
What happened to that option ? Using cavalry to eliminate all thoses dismoralized troops was always very important in battles. Since it's a city battle, they'll all die, but who gets the kills ? Which unit gets the experience ?
And yeah, no horses could be understandable (horses really don't like ships), but no siege equipment is a shame.
I only hope he didn't have any siege equipment because thoses ones are unmovable (once you place them on the battlefield, they're fixed, maybe you need to research something before for siege in boats), so you can't use your troops to "move" them. But what about movable siege equipment, i have no idea.