Buuhan is little more than 2x Super Buu
SS Gotenks is said to be strong enough to kill fat Buu, so SS3 Gotenks is at least 8x stronger than SS3 Goku and fat Buu.
So we have SS3 Gotenks~Super Buu < Gohan > more than 8x stronger than SS3
Buutenks >16x stronger than SS3
Buutenks > Gohan This establishes that Gohan is not 16x stronger than SS3
Finally we have super Buu with 2 kids and Piccolo, let's headcanon a 10x SS3, Gohan is less than 16x so lets be nice and give him a 15x SS3, buuhan is give or take 25x DBZ's SS3.
A 25x SS3 buuhan couldn't possibly be anywhere near DBS SSG, much less SSB tier.
Buuhan is 25x stronger than SS 3
base Vegito is SS3 tier + 50x from SS= SS Vegito being 50x stronger than SS3 Goku
SS Vegito was 25x stronger than Buuhan.