[Edi]

Big changes to AI (which is what rewriting the recruiting AI would entail) asre not likely at this point in time.

If you want more of a challenge from the AI, use the Better Independents mod (link in my sig) or play on e some of the available No Independents maps. I guarantee you that there will be times when you will miss the chaff hordes, especially if you play on difficult or very difficult research.