@DBZ_universe: If we're talking about who's canon then even Krillin solos GT.
LOL! even Yamucha solos GT!
Dbz is built on power scaling, gogeta stomps.
Cell was not even 2 times the power of ssj1 when he fought goku, yet he would rolf stomp fused piccolo, who is above ssj1 level.
So seeing bills knock out gohan with a punch isn't something that the Gt characters can't do. Kid goku has so much Pis it rivals toon force.