I go back and forth on this in my own tying. Even with tailess ones (e.g. a Renegade) I'll often put a slightly smaller hackle in the back. I don't think it's a minority opinion; I've seen it recommended in too many "recipes". My own take on it is that it's not so much for "three point" floatation (which I think is BS anyway) but with a shorter hackle in back it's easier to hook fish. Yours are faily sparse compared to some I tie, and that rear hackle sometimes seem to prevent hookups.

Alan - I always include the tag on a Renegade for much the same reason you use thread there.