So, on a different topic. Slowbro for A rank.
B rank is rather insulting considering you're saying that Slowbro is in the same class as Sylveon and Tentacruel (but maybe they should just be knocked down a tier or two). Slowbro gained a lot this year due to the heavy physical meta and the rise of Lucario-mega. He also is, in my opinion, the single greatest assault vest user. His access to regenerator added with his naturally diverse amount of coverage moves (fire blast, scald/hydro pump, psychic/psyshock, Ice beam, focus blast, shadow ball, signal beam. But this is simply his mixed tank set, which allows him to tank a Solar beam from Charizard Y with no investment as well as take a +2 Dragon claw from dragonite in case you accidentally break a WP.
Even the lack of recover and leftovers is acceptable when you have 1/3 recovery via regenerator. Yeah, he likes wish support, but it isn't essential. Toxic is actually a fine status to have since Slowbro is a defensive pivot and tank and regenerates off all the damage effortlessly. Too slow to bother with the Twave repercussion, and absolutely not bothered by burns, Slowbro is perhaps the definition of tank with the assault vest.
But his assault vest set isn't all he does. One of the traditional physical wall sets allows him to take the physical meta but turn into a wall instead of a tank. With slack off + 3 attacks or slack off, status move +2 coverage moves, Slowbro becomes one of the best physical walls in the meta, especially given his pivot ability and inherent recovery due to regenerator. Dealing with pivots in this meta is common, and uturning on slowbro, though super effective, does not do enough damage to make him lose health after regenerator. He simply has the kind of physical defense that skarmory has, with better recovery, better attacks and a tad less support. He also has the special defenses to take a hit if needed (as long as it isn't SE).
Really, this guy is underrated AF.