Keep in mind, not every Kryptonian is going to be as unstoppable as Clark. Even among his own people Clark is quite remarkable.
As for the non-powered species, I have some doubts. I don't think that without some preptime and the right weapons, Khunds would be able to dent a powered kryptonian. These guys usually get beaten up by Mon-El in the 31th century, along with the Dominators, so I am not sure what their 21th century ancestors are capable of doing.
Although I don't think they've ever followed this kind of logic, I'd like it if, although every Kryptonian could get powers from a yellow sun, Superman would be naturally above them. As far as reason for that goes, maybe something in the rocket that took him to Earth, maybe Jor-El did some genetic engineering to help him survive or maybe he's just a natural mutant... Either way, the result would be Superman being a "super" powered hero even compared to other Kryptonians. He'd be a super being even if more survivors appeared. Now, if they wanted to make Zod a threat on his level, they could give him some kind of kryptonian power armor that enhances his powers or just explain that for some reason he has the same enhancement that Superman does. The oneproblem here would be supergirl I guess, but she'd still be super powered enough for Earth, just wouldn't pull Superman's bigger/crazier feats, which is basically how she's written anyway, even if it's not generally acknowledged.
Superman doesn't have that many opponents, which are a physical match to him, at least pre-reboot. Now you want to castrate his kryptonian rogues as well?
Kryptonian survivors should be rare, not like in pre-crisis times, where it seemed that anybody and his uncle had survived the explosion, but those that made it, like the Phantom Zoners, after some time under a yellow sun should be able to go toe to toe with Superman. Otherwise, why bother with them at all?
mysticism = bull$h7t! SUPERMAN is the champion of science (fiction) and reason, a secular messiah for the masses, specially for the working class of the world.
Okay, so maybe more than a squad. But again, I think the *average* Kryptonian, if one were to survive, would not be on Clark's level. Its not just the raw power, but also the mindset. Superman is like a good watch; takes a beating and keeps on ticking. Yeah, a group of Khunds would not do much against him. But against Joe Average from Krypton? I just see Joe being less powerful and less....hardcore, I guess? than Clark.
Kryptonians' enhanced abilities do not occur naturally. They only manifest when under a yellow sun.
"John Stewart. LAME! ...this guy having a ring is like giving the batmobile to a blind old woman with her left leg in a cast."
"Pym biting Blobs head off seems like something that would have happened when i was ten years old and playing with action figures."
"i always assumed that [the blob] had the same powers as his 616 counterpart because, if simply being a huge fat guy was enough to be considered a mutant then there sure are a lot of mutants in 'real life'. "
Oh, I am sure they would leave a trail of bodies akin to the Viltrimites of Image Comics' Invincible.
Which is an amazing title, by the way. Best superhero title in the universe. Which pains me to say honestly, as I love the current Action Comics. But its true. DC needs to bribe or blackmail Robert Kirkman into working for them.
I'm often of the view that it's not just the solar-enhanced power that puts Kal above all others (Kryptonians, Daxamites, whatever) but the sum of his experiences, too. That, basically, for the most part, none of the others have endured the bullets, missiles, gravity rays etc that Superman has so, for the most part, none of them will be that close to him in overall power, strength, etc.
For example, if you were to take the jeans-Superman from Action Comics issue 1 and shove him into a multi-mega-ton explosion he'd probably die. The one from 8 years later would probably only have his hair out of place. Similarly with the bullet train, the Superman from a few months after the event in AC1 would be able to stop the train with ease.
So, taking those examples, a Kryptonian newly-exposed to yellow-sol-rays would experience an energy boost but would probably get, at the very least, severe bruising from bullets (because they haven't wrestled bulls yet :P ). Higher-calibre rounds may even pierce their skin. A week or so later, however, and their body would have adjusted and their durability levels increased.
It's literally a case of 'whatever doesn't kill them makes them stronger' and, unlike humans and exercise, their levels don't drop from the new 'base' level.
(As far as I recall, the Almeracian Royal Family went through selective and enhanced breeding - hence Kal being the 'best genetic mate' for Maxima).
Actually, Maxima went after Superman, because she became aware of him as Superman and back then he was the only Kryptonian left.
As for Superman's power-evolution, we don't know if that is typical for every other male Kryptonian in this new continuity(Supergirl, Powergirl and daxamite Mon-El certainly are excluded) or it is another case of Superman being stupid and blocking himself, because he doesn't understand the scope of his powers.
It seemed that way in the old continuit(ies), where even as adult he needed Mongul's training to really cut loose, whereas every other adult Daxamite and Kryptonian poweruped almost instantly under a yellow sun and had no problem to cut loose. So even if they start at a reduced level or have less energy-reserves, having the full powers and no mental blockage more than made up for this. And of course, the longer they stayed under a yellow sun, whatever gap there was between them and Superman would grow ever smaller.
As for him growing more powerful through adversity, that sounds more like a hyperadaptoid kinda like Liefields Supreme or even Wolverine nowadays with his healfactor but has nothing to do with the way, his powers usually are percieved. Interesting concept though.
... The Master Of Puppets has spoken.
Goodbye León (november 16th, 1993 - june 12th, 2009). You were, are and always will be the best friend I ever had. I will always love you and never forget you. And please, please forgive me.
Thank you for teaching me about love, patience and caring. Rest in Peace, my friend. I hope that wherever it is you are now, you can run and play as much as you want.