How are enemy stats determined?

[Iluwen]

Does any one know exactly how enemy stats are determined? Especially bab and defence? Do basic enemies get feats allocated to them? How? I have been pondering a mod where bab did not increase with level, but weapon focus could be bought multiple times, so that one had to buy up weapon attacks individually, like skills, and similarly, take the level progression out of Jedi Defense and Scoundrel's Luck, and make them also stack, and available to all classes. However, my concern is that if I change all the cls_att entries to stay at 0, will that cause enemies to not gain higher attacks?