GnW still has strengths in his combo game that far outrank Pit's combo game. For starters, while his grab is slow, it's not something to cough over. The animations are terrible for anyone to properly predict, but otherwise, uthrow,dthrow, and bthrow are all combo starters on Pit, especially uthrow. GnW has an awesome aerial combo game, and in the hands of Dakpo, Lz, etc, it's enough to kill Pit and most characters without a problem.
We aren't an exception.
On the other hand. Arrow harassment can work, but in my experience, GnW can just clank with bacon, and since we NEED to jump for the faster arrows, it helps his angles more than ours.
We do have dthrow > up smash as a semi reliable kill move. And we can build some combo damage on him, but it's usually pretty easy to avoid Pit's kill moves, since they're so easy to read.
As for getting a reliable gimp, good luck. He can jump before OR after his Up B, and the hitbox requires pretty specific timing to interrupt it without getting hit. Besides that, he can act out of it, and fair, nair, both out range all of Pit's aerials and that makes it frustrating.
So I think GnW solidly beats Pit. Not unwinnable. But he has more combo tools, more reliable grab comfirms, bacon to counter arrow camping, and he can gimp us since Glide's glaring weakness can be trumped by any character.
EDIT: I believe Up B loses to Key sweetspot. But stale key loses
