The reason Tangrowth was E was because it was felt at the time that Tangrowth, while not being a bad pokemon, was outclassed in both his Physically Defensive and Chlorophyll roles to the point where there was no real reason to use him on a team. While I still feel that Tangrowth is outclassed if you wanted a straight physical wall due to the far superior physical defense of Tangela after eviolite, I now see just how great Tangrowth is as a sun sweeper. I've never used or been on the receiving end of a Tangrowth (I've been playing Rain Balance for so long) so I guess I never noticed how good it was. Because of Tangrowth's use as a bulky sun sweeper that can counter many of the Sun teams common weaknesses that still has to rely on receiving sun support which can be difficult in a weather war Tangrowth is now B Rank. Blissey I agree with as well. She's better fit to handle sun and hail teams on a weatherless team, and can switch in on more threats than Chansey can due to being less weak to Knock Off and Trick. She also has usable special attack that can be used to threaten a few things Chansey can't. Because of this, Blissey is now C Rank.