By capping Sponsors, the UFC can actually limit what those sponsors do outside of the UFC, say for Strikeforce and or Affliction.
We were talking yesterday, and I think if you look at what Affliction did, if a couple of the key fighters/UFC Sponsors choose to go the same route, it would spell the end of UFC domination. A couple of big names end their contracts and "retire", to only re-emerge in a new org, yeah, def not what the UFC wants.
If you look at boxing and all the Sanctioning bodies that work together all over the world to unite boxing, looking at the UFC and there strong arming, it looks desperate and futile. Sure, some of those S.Bs are currupt, but still, boxing is a united front in the end. MMA is splintered, with the UFC standing on top doing everything they can to stop a expanding MMA market, outside of the UFC brand.