How about the fact that the Yor, who are supposedly tireless robots, are in fact NOT the most industrious when compared to the Thalans. I mean, seriously, robots or insects?? I would think robots would build factories faster.
Maybe, but I can think of two counter-arguments. First, organic life can be a very efficient "machine," when it has millions of years to evolve towards one adaptation like rapid breeding or high production. A beehive or ant colony is a lot more productive, at its own scale, than an automated Toyota factory.
Also, if the Yor have a culture, the culture itself may put limits on this. Maybe they don't want to change themselves past the original Yor blueprint, for fundamentalist religious reasons.

If there actually was a constantly self-improving AI faction in the game, it would probably be unbeatable.