Satan has no knowledge of Ki Manipulation. Master Roshi is the creator of Kamehameha. Master Roshi also is much stronger than he was in Dragonball or Dragonball Z when he had a scouter used on him. Remember his bulk up form. Remember him fighting off hordes of the freeza force?
Powers do matter. Just not zomg power level. Roshi won't eliminate Hit or Jiren or someone like that. But none of the Universes are going to have 10 Goku's running around.
Look at Universe 6 in the Tournament against 7. They had tricks. Botamo had his body that was immune to damage pretty much. Goku just had to King Hippo his ass grab his legs and throw him out. Frost was a dirty Cheater, but his power was Frieza on Namek. Vegeta KO'd him with 1 SSJ Punch. Magetta can't even fly. He seems basically immune to damage as well unless insulted. Vegeta handles him fairly easy and if the arena hadn't be shrunk and boxed in by Vados he would have beaten him even easier. Cabba couldn't even Super Saiyan until Vegeta beat it out of him and then he got 1 shot as well. Now Hit was another monster all together.
But in reality of power Levels from what we have seen int he show Piccolo could have beat anyone not named Hit as well. When Piccolo fused with Kami he became strong enough to fight Android 17 evenly and Imperfect Cell before he absorbed another town. This was far beyond Frieza who out of Cabba after he transformed is greater than anyone on Universe 6.
Yes in scale of Power Level to Early Dragonball Z (when power levels became a thing) In theory Goku and Vegeta could power up and the surge of energy might be enough to eliminate people. They might have some weaker people get eliminated that way, but I doubt that.
Gohan also owned his opponent. If he hadn't been blinded and poisoned by the tactic and strategy that was used against him it wouldn't have been a fight. Buu also owned his opponent. Mostly because if you can't kill someone or ring them out Buu is unbeatable in this format because his body always regenerates.
Also Trunks didn't go Blue. He dyed his fucking hair and went False God or maybe even Broli Super Saiyan.
At the end of the day it is an animated series and not reality so while we can debate over and over again it is what it is. Maybe Goten and Trunks would have been fun to see, but they are the only other options Universe 7 has since Supreme Kai sucks at his job and knows of no other strong people in the entire Universe. Be happy you get to see old favorites get some run. Roshi will be fun in the tournament and he will probably get eliminated rather early, but who knows.
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