I noticed that HUGE graphic bug (huge because It's hard not to see that in battle!) : The AI Dwarves had an entire army composed of... Orcs!!!
When I met them in battle, almost the whole "dwarven" army was made of orcish units. They stille had dwarven banners. That was awkward...
The most was that their models had no "skins" (in term of modelization of course) so they were all chromed!
Tuning Orcs
That wasn't a big deal since my own orcs beat the crap out of them anyway, but that is certainly a bug.