That's not entirely accurate.
The latter may or may not have a better AC, depending on how he's kitted, but he will definitely have an advantage over his bumbling counterpart with regards to initiative and the ability to soften up foes with ranged attacks before engaging. This could be especially important if the enemy in question plans never to close to melee range at all.
And if we're talking fights on certain kinds of difficult terrain where it's difficult to remain upright...
That's all situational though. In a bog standard fight, there's little to no difference and that runs counter to my experience.
I've studied martial arts. I've sparred opponents who were on par with me strength-wise, but significantly faster than me (higher Dexterity). IME, it's a huge advantage, even leaving out defense. Someone with both speed and coordination can come at you with such a flurry of attacks that you're hard pressed to defend, much less counterattack.
It doesn't require being able to throw the first blow. It doesn't require a ranged weapon. It certainly doesn't require unusual terrain. It's simply a matter of having greater physical capabilities.
What it comes down to is that ability scores are not a good simulation of reality. They're a sim aspect of the game, but they're a poor one.
Wisdom covers willpower, common sense, and perception (among other things). Have you never met someone in the real world who had no common sense but was stubborn as an ox? Or who had good common sense but would walk into walls? Clearly then Wisdom is a gathering of traits that are, at best, loosely related.
I don't have an issue with you liking ability scores from a game play, traditionalist, or other perspective. Let's be realistic though; ability scores aren't realistic.