The tactical maps aren't really even big enough to have city walls.  The combat area is tiny. 

Yeah. Catapults are a great idea when there are fortifications that need catapultin'. But until we get some of those, they're pretty terrible

I was pretty floored when I saw no walls in city siege Elemental tac battles.

The catapaults I see on ridiculous are pretty effective with a meager 32 attack. They can miss 1/3 but attack 2-3 times each per turn doing 30 damage per hit. This includes highly defensive units such as a squadron of elite dragons. Since there are usually 3-4 stacks they do around a 100 damage per turn if not more.

This is with the ogre tanks in front with 4000 hp and 300 attack with various other archers etc.

Not to mention I get attacked by 2-4 armies per turn I'm finding it pretty effective.

Edit: To give myself a harder time I'm playing on a small map with a 1 city policy. Thus the other races have become exponentially more powerful. Oddly with this my game isn't crashing. I believe the crashed might be related to the player's field of vision/cities?

I had an issue with the catapults in a city I assaulted. It was a stack with a Hp of 573 and it just stood there. It would get 4/5 the way dead and the game would crash.. I tried to auto resolve and every1 died...