I dont think that there is an easy rule of thumb but routes should maintain their own integrity. Any time you think which way now, mean they are probably to close. If you had 2 flakes or cracks next to each other then they may only be 2m apart and maintain there independence but on an unfeatured slab they may be 5-10m plus. preferably the rock defines the routes by cracks, corners, flakes, scoopes, weakness, aretes, steep bulges but it is more difficult on certain types of rock.
PS, i dont know anything about the specific routes in question |