Here's the ep where kid buu appears. Vegeta and goku cant tell if hes stronger or weaker. But Supreme Kai literally says: "This Buu is even more powerful.
https://www.dragonballclub.net/dragonball-z-episode-277/ 11:15
So either the dub is wrong, or the anime is inconsistent, or the manga itself is inconsistent.
But I see no reason to not take the character literally. He's Supreme Kai he knows this being better than anyone else.
So without proof of a different original text in the manga, or word from Toriyama himself, this dub is simply inconsistent and illogical, and if it's the same in the original material, than the material entirely is inconsistent and illogical.