And while you're at replacing some original OOB, better talk to the devs, because the game is (and has to be) hard-coded to use certain formation at certain times - there's no way to set these things in outside files.
You can, of course, restrict the availibility of some units to certain time spans - the AI will not get anything that is not in service yet/any longer. But this does not keep it from trying to buy the same formation over and over, as long as it has building points left, what will most likely result in very strange force compositions
no good news, but maybe a bit helpful
