You're right, of course, and boy, did I state that very poorly! What I meant to say was that the Framers might have looked to the Iroquois, I didn't mean that it was their basis or their inspiration. I don't know what to think of the claims that Jefferson studied it, etc., but I think that even studying it doesn't mean that the basis.
Perhaps I could word it thus: the Iroquois might have influenced their thinking to some extent--that might be possible--but I don't believe it's the foundation.
FYI, here’s one of the seminal books on the Iroquois League, written before political correctness. :)