Government would be greate
I think the government idea is very interesting.
I think this was said before but ill clear it out a bit with and example
For example you humans. You have one king however there are many other kings for other human factions. There is an alliance and you have a joint council, or you all individuals and its free for all. Lets say you conquer all other human kings since the opposed your rule, so you conquer them giving you a bonus for that race. So now you have all of mankind in you hand, and this should give you a significant bonus of some sort. But it should also provide you with negative impacts such as harder game play, more enemy's and of course more wars to fight against other races and to look after you cites, economy etc
The type of government you are can be preset when you start but your actions can determine the outcome of you nations government slowly.