You should try out SemiRandom by Ballbarian in any of his sigs. You can use it to set up the map by giving the AI's properly equipped SC's and thugs at the beginning. That way they won't be crappy built thugs and sc's. You can also give them starting armies. It's much like what you are doing but you can then use random starts so at least you won't know everything they might have.
There are some great threads on how to build pretenders for the AI as well. A bunch of things are critical so that the AI doesn't send it's pretender into the arena. Best is probably immobiles. I'll link the thread where I asked the same question as you but I approached the solution differently.
http://forum.shrapnelgames.com//showthread.php?t=44008
Re: Making SP harder
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