It would be akin to rejecting him as a prophet, basically. You'd definitely be playing twister trying to make it work. It would be bad theology because it simply wouldn't work unless you turned Islamic doctrine into a pretzel. I would call it bad theology; this is a phrase perhaps more used in Anglican and Catholic circles but it does have a meaning, and is usually applied when the theology is ill thought out, usually on the basis of a bad reading of scripture or something that would violate philosophical norms universally held within the faith (in this case monotheism and the writings of the Fathers).
I can see why extremely unorthodox positions sometimes cause controversy, but considering that some of them have resulted in reform or increased support for civil rights and freedoms, I just rarely find myself objecting to them or dismissing them as "bad theology" or anything of the sort. At worst, I would say that some of them are clearly inconsistent with the intention behind the text or the contextual meaning thereof, but I don't see that as necessarily harmful unless it leads to propagation of harmful beliefs or support for harming any given person or group.
My background, which is from a highly conservative Islamic region, undoubtedly influences my views on this, because I've seen so much hatred and support for persecution being passed off as orthodoxy and tradition and being enshrined or defended on that basis, and I've seen so many attempts at reform and advancement of human rights being dismissed as "heretical," "whimsical," "dishonest," etc. I've developed a staunch sympathy for individualism in one's worldview and diversity of religious and ideological interpretations mainly as a result of that.