Although I have my doubts, Piccolo and Krillin thought they could defeat Majin Vegeta SSJ2 even Fat Boo (On just before fight Majin Vegeta). According to the anime and manga, Krillin says that with that on Fat Boo became even more powerful.It looks like Goku knows that the true power of Fat Boo is even beyond, that's why you want to team up with Majin Vegeta. Personally I have this: Gotenks SSJ (Pre)> Fat Boo (Enraged before splitting)> = Goku SSJ3 (Boo)> Fat Boo (True Power / when it burst against Majin Vegeta) >>>>>>> Base Gotenks (pre) >>> Goku / Vegeta Majin SSJ2> Fat Boo (On just before fight Majin Vegeta)> Fat Boo (First on / against Dabura)> Kid Gohan SSJ2 (CG)> = SPC> = SSJ2 Vegeta (Majin pre ) >> Gohan SSJ2 (Boo) >> Fat Boo (initial) >> Goku / Majin Vegeta SSJ.Captain Cadaver said:The level Fat Boo used against Dabura, Gohan and Kaioshin was strong enough that Goku advised him and Vegeta teaming up, whilst Vegeta was unsure about his chances of survival against him. Boo's stronger based on that.