12,000? Even when I have positive culture it is never more than 1000. But, hey, everyone plays this game differently! There is no wrong choice!! I think I do better with more houses and more workshops than having the culture above 100%. It really depends on whether you care about ranking points (you get zero ranking points from culture).
What does it do the production of coins and supplies? It stays at 100%. It never goes below that. But you can't build anything at all while you are negative and you have to get un-negative again to start building upgrades and such. So, it isn't a long term strategy, but the orcs were such a slow chapter, that it didn't make sense to me to take a year to get through it. And that is about how long it would have taken if I had devoted the same space to the race that I did in fairies and dwarves. (which was about 3 expansions.)