I think you overstate the impact that Ganon's chaingrab has on this matchup. Sheik has all the tools to avoid getting grabbed - low sprint / DA animations, a versatile crouch, and a projectile that forces Ganon to approach on her terms. A competent Sheik player will simply not be getting grabbed enough to justify picking those stages in view of their downsides, which have a much more consistent effect on the match. These include lots of horizontal space that allows Sheik to play Super Left-Right Bros., and a lack of platforms that make working around needles quite difficult (not to mention the universal benefits that platforms lend Ganon). So, assuming YI / WW are banned, BF seems to be the go-to answer, with GHZ and DL also posing unique benefits and drawbacks. As Sheik, PS2 and FD are your first choice, DL and SV your second (not taking into account non-universal stages).
