Basically what Neo said but in less detail.
I think you're basing this too much off HOW and WHO you're facing the pokemon with, rotom, rather than the sort of strategic pokemon you use against them. Every team has it's nightmares, and just because you had hell with some, doesn't mean "oh hey this guy's too tough make another tier pls".
Please, actually test out the pokemon yourself before whipping out the ban hammer.
On a side note, Sunkern is too strong. It needs it's own tier above ubers.
Edit: Oh, and you're not even suggesting enough pokemon to fit a whole tier. You could, at best, only salvage around six of them. That's laughable for a whole new "tier".