One problem with that plan is that Cruz is busy getting his people into the committee spots as well - and with the Cruz people and the RNC people holding the majority on the Credentials committee, how do you think Manafort will fare? Unless he has documented proof of crimes, I don't think it will go too far.
The Cruz people are guilty as sin. They are guilty of organizing early, participating at the local level, injecting themselves into the system, working their butts off for months on end, and never ever giving up. These are exactly the kind of people I want working against Hillary and the same kind of people I want running our government for the next eight years. I damn sure don’t want another celebrity type who leads from behind.