“Let Hillary and I sit there and just debate, because I think the system is being rigged,” Trump said on Monday
I think this makes good sense. The only necessary thing might be a panel to as follow up questions and a referees. Lets say a panel of four drawn from universities, business, etc. to ask follow ups or even respond to questions form the debaters. The panels could be chosen by the networks or by the debate commission. People I might imagine include Colin Powell, Elon Musk, Bill Gates, a prominent rabbi, an iman, ????
The panel would be chaired by one of the four designated coiffed heads from the networks but she or he would only act as the referee.
One huge advnatge of this, perhaps disconcerting to both Trump and Clinton, would be the absence of applause .. except when requested by the referee.