Best co-op races to play?

Want to play a co-op campaign with my bro from start to end. Preferably two races close to each other so we can aid each other in combat and sieges. Anyone have any good suggestions? I have all the DLCs and so does he. Both beginners, have recently finished rome 2. Played a bit of the vampires co-op and it was fun but don't really like the vampire theme/units.

Total war warhammer 1