It's very easy to find out where a load was originally brokered. This is why you see many owner operators that used to have their own numbers leave Mercer after a few months. That's because the O/O can do that himself!! Not to mention he can find loads and not be totally dependant on a broker that might or might not opt to work up some loads.
I know there are some dann excellent brokers at Mercer. But there are some lazy ones that just wait for a phone call or snipe the load boards.
Other than buddy hustleing you will rarely see any decent loads. Amazing how Mercer serves up a line of crap to sell seasoned owner operators that suspend their authority only to see through Mercers game playing. Then the O/O leaves Mercer quickly and gets his numbers back.