So Total War: Warhammer is good. Which is good. It's not great, but what did we expect?
It has a lot of potential, what's there is fun but deep enough to keep you interested. There's a lot of room on the edges of the map for expansions, which is just part of the parcel now with Creative Arts. Get ready for 20 more DLC's over the next 2 years.
There's easily room for Ulthuan and the eastern coasts of Lustria and Naggaroth as well as plenty of space down south towards Araby and space to the East past the mountains where the Chaos Dwarves dwell.
I notice that Athel Loren is suspiciously vacant of settlements at the moment so expect wood elves soon.
With mods, Radious Total War and Radious Total War Units as well as a few others, the game is quite good at the moment but it'll only get better. If you want to wait for a more perfected game experience wait until it's on sale with a few more DLC's released.