I
completely disagree with a few of these last changes.
For one, Crobat is
definitely S-tier material; refer to
this post for my reasoning. Cofagrigus, while great, is not S-tier material. Why? It's one of those Pokemon that performs excellently against the average ladder player, but not nearly as well against one of a higher caliber (it's not easy doing a two-turn setup). In fact, I don't even think it's A-tier material--high B-tier definitely; A-tier is kinda questionable imo, but I don't feel too strongly about it.
(Why did you move it down anyway? No one's even debated it being S-tier)
Weavile and Porygon2 should stay in B and Zapdos should move down to A.
As for the whole Nidoqueen vs Nidoking debacle: neither one is A-tier worthy imo. Nidoqueen is high B-tier and Nidoking is low B-tier.