How many factions are there?

I was just thinking... What if, for example, Heroes 6 had around 4 factions, but they were very carefully and thoroughly developed – abilities, balance, unique heroes and magic, characteristics, and development paths. And, of course, lots of neutral creatures. For example: humans and Necropolis, demons and elves. It doesn't matter which ones.

How would you feel about the game? Assuming that the number of factions would increase with an expansion pack?