Disagree heavily
That the discrepancy in effectiveness between one class in Dnd and another is due to access to different abilities and spells instead of of one just having raw, higher numbers doesn’t mean that discrepancy isn’t there.
And it is there within classes too. If someone makes a standard two handed weapon fighter, and someone else makes one that dual wields a whip and a hand crossbow because they thought being Indiana Jones would be fun they are going to be very different in their effectiveness. Particularly at level one, since the wired build is going to need all kinds of feats before they become remotely effective. I’ve seen it over and over again from a player of mine who always wanted to do whacky builds that will “start to work at level 7”
Now we are gonna reach a point where i agree with you, and where i think GMs need to be willing to be a little firm in SCRPG since players are roleplaying as character with, well, super powers.
Hitting every minion in the scene for nine every turn would indeed be OP. I don’t think its a thing one character can reliably do every turn for a few reasons
First off, Nearby minions doesn’t mean every minion in the scene, it means a group of nearby minions. “I know you can run at mach 7, but you still need to pick if you want to punch every minion on the north side of the park or every minion on the south side of the park. It takes takes enough of your focus to hit just the bad guys with just enough force to not destroy the entire park that you only get one group” This does still mean the speedster is doing much more then the person just hitting one minion, but they aren’t solving the entire scene on their own.
Next Getting up to 9 damage reliably to me means either you are getting other players to boost you, or you are using a red ability. If its other players boosting you, I think thats fine. If two or three players are spending there turns in tandem to delete a group of minions well that is in general what minions are there for.
If its a red ability it means either you are near the end of the scene, you are wracking up twists, or you are using collections. The first two are fine with me, the last one is where the GM needs to be a little firm.
collections require roleplaying to active. “I draw upon the memory of the last time we fought the Duke of Destruction to dredge up the rage to use my red ability without a twist.”
If the player next turn tries to use the exact same justification to do the exact same thing using either a a different collection or the same unticked with Break the Fourth wall the GM can say no, that well of dramatic tension is dry.
All of this is getting far afield though. I largely agree with you. There are power soruces and archytpes that are stronger then others. There are abilities within those that are stronger then others. There are principles that are more easily used then others and there are -certainly- red abilities that are stronger then others. But at the end of the day i could make a party of four characters in Dnd trying to be quirky and do a special thing that wouldn’t be able to clear one of the starting adventuers. I think a party of three or four SCRPG heroes using all of the worst power sources and archtypes would still be able to make it though the starter kit.