No problem. Actually, I think it's a valid digression.
The problem with Superman is that his special abilities are arguably more racial than martial, like a dragonborn's breath weapon or an eladrin's ability to teleport.
Which then raises a question that Quickleaf also touched on in his post: what are some examples of epic-tier martial heroes? Beowulf? Leonidas? Guan Yu?
Epic Martial Heroes? I'd say characters like those in Crouching Tiger, Hidden Dragon, House of Flying Daggers and Hero. But then again, I'm all in favor of a monk using the Martial power source.
Western epic martial heroes would be legends like Beowulf, Herakles, Samson, David and King Arthur.
Beowulf - Fought aquatic monsters underwater holding his breath for hours.
Herakles - Helped the gods fight the Gigantes, choked an invulnerable lion to death, sired hundreds of children.
Samson - Brought down an entire edifice through strength alone.
David - Felled a giant with a single well-placed shot.
King Arthur - I recall at least one instance of La Mrt d'Arthur where he severed a giant's leg at the knees so he could reach his head and behead him.
So while Heroic and Paragon martial heroes stay within the laws of physics (even if they do push things a bit), Epic martial heroes break the laws of physics through sheer awesomeness.