Fair enough he was younger, but he never seemed as smart as a Superman should be, and at times unwilling to use his powers, sometimes ashamed of them, and become the superhero he was meant to be.
Also I think Chloe and Ollie had as much to do with the Justice League as Clark.
True, true. In terms of how the series was executed, Clark didn't come off as very Superman-like. But the whole idea was that he hadn't yet matured into Superman. So I'm not sure it's fair to compare him to the other incarnations of Superman who are in their upper 20s or 30s; any comparison should be to what they accomplished in their own teens or early 20s. What do we really know about that? Pre-Crisis Clark was Superboy and accomplished quite a lot at that age. Donner's Clark was in some kind of intergalactic learning trance or some nebulous thing for something like 18 years, which doesn't strike me as accomplishing much on behalf of other people. Man of Steel
Clark, and also Birthright
Clark, was wandering the world and searching for his purpose while doing clandestine good deeds. DC Animated Universe Clark is something of a mystery where that part of his life is concerned, but we know he didn't reveal himself as a hero until he was older. Ditto for George Reeves Clark. And so on.
So I'd say it's a mixed bag. Some versions of Clark accomplished a lot in their teens and early twenties, others not so much. Smallville
Clark probably falls somewhere in the middle.
(And I'd argue that there are two separate eras of Smallville
-- the first 7 seasons from the original showrunners, in which Clark resisted embracing his heroic potential for a ridiculously long time, and the last 3 seasons from a different set of showrunners who finally, finally
abandoned that stagnant characterization and had Clark embrace his heroic role. It doesn't really work to treat the whole thing as a single piece, because it's really two very different shows with different approaches.)
Back on topic, there is also the All Red Rangers episode. Forever Red.
Except those weren't alternate versions of the same person, or even different bearers of the same identity like the various Flash team-ups in comics -- just different people who wore the red color usually associated with leadership on various distinct Ranger teams. It was more like an all-star team. (I mean, yeah, they were all "the Red Ranger," but one was the Red Mighty Morphin' Ranger, one was the Red Zeo Ranger, one was the Red Turbo Ranger, etc.)