It's not just the Alterians, Drengin and Koraths. Since the Expansion all AI Races except of Terrans (although sometimes they also play as push overs, but not so often), Torians (always strong), Thalans and Krynn (also strong in every game) a merely push overs. The rest just dosn't colonize much nor they show any intentions to become at least a minor threat. It is realy frustrating.
Today another game on painfull went down the lane because they're just not formidable, much worse as on DarkAvater. And the most ridiculing thing is: especially the AI for Torian and Krynn show that they could be more than capable to show off a good colony rush and aggressive expansion on the game. So why the hell can't the other races cut anything? It's really ruining the sand box games especially on the larger maps!
To get back on todays game on painfull which I quit out of frustration short before the colony rush would stop (so no invasion wars yet). It was a game on a immense map, I played Yor. Up until I quit the session I settled 43 colonies easily (still had quite some free worlds to aim for). At that point Torians had 55 and Kryn 53. The rest? Drath, Arceans, Drengin, Korath all between 10 and 15 - wooooaah impressive. And it's not the first game where this happens to me it's like every game I play. It's always the same scheme, always the same big players and always the same stupid, utterly useless sidekicks. And it makes the game so unbalanced. When you start far off the AI you can settle like crazy because most of them don't expand at all which opens the room for you. On the other hand, sometimes you start cornered by near AI players and your expansion possibilities might be limited. So on a immense map the colony rush might end let's say at 40 colonies because your surounded by AI players and they slowing down you colonizing plans - which is fair enough. But while holding off your expansion or slowing it down they almost don't do any colonizing themselve. They stick around with 10 to maximal 20 colonies, forming a nice belt around your planets - while on the other side of the galaxy there is one of the top AIs getting 100+ colonies without any problems because all the others just don't do their job...
I really really hope they gonna boost the AI a lot in patch 2.0, right now it's bit of a fun killer. This is just the colonizing part but there also some other issues with the AI but they are rather minor in comparision to this.
Anyway, now I feel better after putting off some steam 
