Why don't U just change their Ai to Krynn Generic Torian or Terran so the Ai will make more ships.
The Torian (and Iconian) AI is considered to be broken. It knows how to expand, but most of it's worlds will stay empty, because it doesn't build anything on them, except for a Starport. In effect, the Torians and Iconians are strong at the beginning, but the longer the game lasts, the weaker they get.
U could change the Korath giving him a Generic Ai
Bad idea, if you want the Korath to keep using their Spore ships. The Korath AI is the only one using them. Also, the Korath AI (same as the Drengin and Yor) is pretty good at using morale improvements. You would loose that too, if you change them.
though the Ai don't know how to play the Yor
While not perfect, the AI does know how to play the Yor in my games.