no theory is ironclad (otherwise they wouldn't be theories), the problem here is that in order to keep some of them alive we completely ignore the only facts that are presented to us.
mine was a general discourse, gay Chad was one of the examples. but as for the latter, everything starts from Sage finding some woman's panties. this is a fact, not a scene to be interpreted like Mel and Sara's reaction to sage and Chad's breakup. and yet it remains completely ignored, because it doesn't fit the theory. theory first.
and we're talking about a basically secondary aspect to the story, why Chad leaves Sage serves to give depth to the story, but one reason is worth the other
we can always find out that Chad's lover is a cross-dresser...