Rutherford wasn’t perfect (Brady is more conservative) but he was the biggest threat to Rauner and has already won statewide.
That’s why the combine unleashed the “scandal” (that he sexually harassed/tried to gay rape some ugly bald democrat) and destroyed him.
If it had just been the democrats alone they would have waited to see if Rutherford won the primary and then unleashed the scandal in September.
But the fact Rauner decided to completely destroy Rutherford's reputation with a manufactured Herman Cain type "scandal" seems to be pretty clear evidence to me that he ran for Governor without the combiner's approval. He posed a threat to them since he went against the "only candidates who love planned parenthood can WIN statewide in Illinois" propaganda, and they needed him out of the way.
Dillard supporters utterly despised Rauner, but there was no similar effort to "take out" Dillard from the Rauner camp. The combine takes care of their own.