Well to be fair, all of these heroes whom you describe, are more like specialized thugs, than true SCs. None of them could "take the damage" as well as dish it (except perhaps Sauron, but that was so obviously a lucky critical strike
). For example, Legolas may be analogous to Lugh the Long-Handed perhaps, and well geared Lugh can really wreak some havoc - but put him solo against 500 men and he'll be someone's ***** right quick.
If Leonidas had been a Dominions SC, he'd be 20 feet tall and have Boots of the Behemoth - then maybe he'd have won Thermopylae, but as it was, he was just a very capable leader, and a good soldier. As far as we know.
But, I think we can safely rule out the 20 feet tall part, and the F9/E9 bless. >.>