Performance, just put all the top tiers together on a list that are or will definitely be better and are not as easy to tag.
Kaidou, 3 OG Admirals, Garp, Mihawk, Shanks, Blackbeard, Dragon.
Then you have wild cards whose role is not clear yet and have not been shown in a real fight like Imu, two new Admirals, maybe Gorosei, Shiryuu (who will at least be low top tier when he fights Zoro), stronger Sabo, heck post Wa No Luffy who at least hits as hard as BM but does not have the glaring weaknesses.
So yeah, top 10 seems far-fetched, top 15 ok, top 20 definitely.