You're facing a knight in heavy steel armor, and you both swing and bash at each other with your swords. In the end, it boils down to an endurance test. The sharpness of your blade means nothing because you're swinging it against resilient steel, and your razor edge eventually grows dull. Your fine slicing and dicing weapon has become essentially a club, and your only lethal option is thrusting into a weak spot in your enemy's armor.
You got the part right about fully armoured fighting being more about thrusting. However, the [European] 2-edged sword was never used anything like a club except in a particular technique that uses the cross and pummel to deliver a blunt blow. If your edge would get bashed up and such and didn't do any significant damage, why should you even waste your energy trying? I would focus my energy on getting a thrust in.
Though, that is against plate armor. A good longsword (or even arming sword) can cut chainmail and can definitely thrust through it. It takes a good stroke and proper technique, but a good sword will do it.
MnB doesn't allow for a good thrusting fight with half-swording and everything, so I think it makes better for gameplay to have swords to cutting armor. (however there isn't good plate armor in multiplayer)
Maybe that's what you were trying to say

But just in case, I wanted to clarify

It holds a razor-sharp edge
Another misconception for European double-edged swords. The edge of a longsword or arming sword was certainly sharp enough to make a cut or to inflict a terrible wound when swung, but it wasn't so sharp that you couldn't grab ahold of it with a good grip. The cross-section of the edge was actually shaped similar to the cross-section of a pecan (i.e. more rounded). This was to help protect the edge but also to allow a swordsman to half-sword without fear of his hand being cut. Don't let the poorly researched (and poorly balanced) Cold Steel replicas fool you.
Nobody in real life would try, or be able to, block a warhammer with a shortsword, or any sword really.
Especially not a warhammer swung from a charging horse.
well, in foot combat, a shortsword could fairly easily bind with the ridiculous maul thing in MnB. Then the man holding the hammer would probably do better to let go of his ridiculous "weapon" in an attempt perhaps disarm or wrestle with the swordsman. Of course, swung from a horse... that's a different story

this is brilliant. this would give heavy, slow, minimal reach weapons like the war hammer usability.
I think that if they had better armor in the game, the hammers would be more usable. The current 2-handed hammer is actually kind of ridiculous though. A proper warhammer would look much more like the military pick does.
gradually degrading damage output might be a good idea though (though the thrust should not degrade much if at all). It would encourage people to pick and choose their strikes more carefully. I don't know; maybe it would slow melee down.