Collins and Lopez aren't the same thing. It isn't only about being able to shoot the outside jumper on offense. It is being able to play on the perimeter without getting exposed as a stiff. Sure, on offense you can have Lopez stand on the 3 pt line to provide spacing. He still won't be able to do a lot of the other things that a forward can do like drive and kick, stay with guys on the perimeter, run a fastbreak, etc.
Well, you were the one that brought up the Durant comparisson. The 7'4" without shoes will get optimized the closer to the basket he plays, not if the stands on the perimeter shooting 3's at a 28% clip.