I don't know why it would be without Silva seeing as he's talking about fighting again this year, but assuming it is;
Belfort pre TRT was a wrecking machine, only stopped by a prime AS and Machida won (and defended... technically) a title in a higher weight class and has gone undefeated and looks in the best physical shape of his career since dropping down.
Looking at the rankings, top 15 p4p IMO: LHW has 1, HW has 1, FW has 3 or 4, WW has 1 or 2, BW has 2, LW has 3. Obviously subjective.
Weidman, Silva and Belfort are solid top 10 p4p IMO.
RE TRT: The other commissions will follow suit regarding not grant TUEs but the testing will still be sparse and inadequate. They're still using piss tests AFAIK. Also the effects of PEDs aren't just acute, they're cumulative. He's had several years of impossibly (naturally) intense camps to improve his skills.