As someone who has actually used Mega Gallade recently I can't really say that it deserves one rank over another as I think its more on par with the rest of B rn but its qualities and struggle to find an oppurtunity to mega and set up fit more along the lines of B- imo. You have to realize that if you use Medicham you have an instant wallbreaker who can apply pressure throughout the entirety of the match granted they don't have a Mega Sableye. Mega Gallade on the other can apply even more pressure than MegaCham if it is able to set up a Swords Dance which can be moderately difficult. Unfortunately as cool as getting Mega Gallade to +2 its hard to offer it any credibility when it simply troubles versus the same things MegaCham struggles with. Also please don't mention Shadow Sneak. It only helps out in a matchup versus Zam or Auromoth and maybe Latios if you dislike speed ties. That said I may be sounding a bit too harsh on Mega Gallade it still does peak over Keldeo, base form Crucibelle, and Garchomp and can power through Slowbro if it wishes so.