Looks very good!
My thoughts on the buildings as they relate to my artwork.
My artwork is the basis for the Wonder video that I am creating for each wonder. Hopefully we can match up, but if we do not, it will not be a disaster either. For one thing, both of these elements (video and ingame sprite) will not be dominant visual elements to the player. Videos might be viewed once during the course of a game, if even that. And how many players spend a lot of time zooming in and comparing if the video matches the ingame art...
It's nice to sweat the details, but it is also one of those things that we can easily go overboard on too. The time spent on trying to exactly match things up becomes wasteful.
So my thought on the Seat of Moradin...don't sweat the statue too much.
It helps if you think of most of the buildings in the game as complexes instead of individual buildings.
It would be nice to try to incorporate in my bone pyre into the Crypt of Souls, but it is not necessary either. I have no problem with the way you have the Crypt now, and my artwork merely focuses on a small (but dramatic) part of the Crypt.
If I am building a School of Divination, most likely it will be similar to a regular university, with a lot of different buildings on it. That allows for some flexibility for the art team too, and if my artwork does not match up with yours, it's just that we are focusing on different buildings in those complexes.
Hope this helps streamline the process...