The reason I like the idea of ranger as fighter subset (though I don't think it will ever happen) is that there is nothing in the fighter chassis that is "anti-ranger". The flavor of a fighter fits perfectly well with a ranger, they are both strong fighter characters after all. You just need to add in the core ranger stuff on top.Fighters are generalists that are deadly all around, but one of the few consistent themes that has managed to stick throughout the editions is that the Ranger is a specialist that can take down a specific type of creature better than anyone else.
I think between a more nature/survival fighting style (or maybe a "favored enemy" fighting style), and a "ranger" subclass, I think you could hit the key notes of a ranger pretty darn well.