Perhaps but the primary debates sharpen a candidate and prepare them for the final debates. With proper prep and discipline Trump would likely make an outstanding debater.
He doesn't have the temperment or the personality to acquire that kind of self-discipline in so short a period of time. You're asking him to change the habits of a lifetime. Look at any of his answers to any question. He goes off on half a dozen tangents and can't wrap any answer up in less than two or three minutes. He will not do well under the format planned.