Well, I prefer to take a more aggro snake (probably why I lose so much with him). Anyway...
Maybe someone can critique this strategy for most ledge opponents.
1) Stay near the ledge. The very fact that you are nearby has to force them to consider more of your options. Staying far away allows them to solely focus on getting off the stage and hitting you with arrows. Or avoiding nades.
2) You should attempt to regrab the ledge from them or run up shield. Present some sort of target to break up there camping. Again, it breaks up their stupid arrow pressure. Do it when they regrab the ledge or something or have to waste multiple jumps to get back. There are lulls in his attacks that give you free time to move in, get nades pulled, etc.
3) You should be able to power shield arrows off the ledge. They cannot mix-up timings by rotating or anything. They pull off from the ledge, they jump above above the stage... you should be expecting an arrow might be coming at that point. Seeing the bow pulled and arrow flying should be all the confirmation you need to know to shield.
I suppose due to the nature of his camping. You can camp him while he is on the ledge from far away. If he comes up, you might have timed a nade to hit him. Although, your opponent can watch you too and avoid those... I prefer to avoid something like that and prefer a more upclose approach with baits.
Well, here are some ideas. Go to town against anti-ledge camping :D
Edit: Has the term gone from planking -> ledge camping -> ledging? lol