Congratulations, you've found two champions that are melee (in the case of Rumble, only technically) who can win/go even with Darius in lane. I fail to see how that validates your point whatsoever.
Renekton is known as a very powerful lane bully who scales terribly. If Darius didn't exist, Renekton would be the one accused of that. So really, Renekton surviving lane against Darius doesn't mean anything.
Rumble may have melee auto attacks, but his laning phase is not melee in any way. He has no mana to manage, his harpoons let him CS safely from range while his flamethrower lets him cs safely from up close, matching any trade while not taking aggro. He is likewise often complained as oppressive toward melee laners.
In short, your two examples are two of the most obvious non-ranged champions that could do well against Darius. No wonder you don't auto-lose lane to him.
Try playing Hecarim against Darius and make the same comment. That's just the worst example, I would argue Poppy, Nasus, Mundo, Trundle are all also incredibly weak matchups (although mundo can at least throw cleavers). It's not like it's literally auto-win, it's moreso that Darius has a large innate advantage in most melee matchups that make laning phase incredibly boring for whoever he is up against (just stand back, farm from range with whatever abilities you can muster, and otherwise farm under tower and avoid being grabbed at all costs).