I still don’t get how you’re hung up on superhuman. We already used the rogue as an example of the superhuman stuff they can do without needing quantify it any more.
Why can a rogue dodge explosions? he’s a rogue.
The Rogue description supplies flavor: "you can nimbly dodge out of the way". It relates to reflexes.
Sometimes these reflexes seem "superhuman" in certain situations that seem impossible.
But there is a doublestandard. What is ok for the Rogue, is often not ok for the Fighter, in the eyes of many players. The Fighter is supposed to be strictly nonmagical. I dont agree, but many players say this, including in ENWorld forums.
Why can a fighter leap across a chasm and cleave a foe? He’s a fighter.
As of now, a Fighter cannot leap over a chasm. A chasm is say 300 meters across. A Fighter cannot leap this.
Should a Fighter be able to do so, such as emulating Hulk? Yes, of course.
As other people have said, I don’t see the line you’re drawing between what super abilities need justification and which ones don’t. All your examples seem arbitrary to me.
It seems we just have different preferences.
As a DM, I rely on narrative adjudication. That means. I describe a scene, and the players describe how their characters interact with elements within the scene. Everything is story. There is no mechanics. If the players say something, and it seems plausible that it would work, then it does. Automatically.
The only time mechanics ever happen is, the narrative may or may not work. Then dice start rolling.
So, as a DM, knowing the flavor for why something can happen, is actually more important than having the mechanics for it. At least, the flavor happens first, before any mechanics can become possible.
the 3rd level Archetypes already cover all the different fluff. I guess that’s why they’re called archetypes.
Narrative interactions that are generally possible in reallife are assumed to also be possible in the game mechanics.
But the reverse is untrue. If the players want their character to do something that is overtly impossible in reallife, there needs to be an explanation for how such a thing might make sense.