Hollywood said:
I am the DM.
While informative, it doesn't get you off the hook. Nobody wants to win the "Unreasonable DM of the Year Award".
Hollywood said:
And I asked because I was torn....
Understandable. Logically, sneak attacks can seem kind of wierd depending upon the situation, or who's doing the sneak attacking for that matter.
Hollywood said:
Well using a sword effectively in combat takes concentration too.
What about swinging a big battleaxe with all your might? Sweeping a giant warhammer back and forth, swatting your enemies away like tiny little bugs? Neither of those require concentration. Instead, they simply make use of blind fury, or more to the point, rage. This is not to say, however, that such weapons cannot be used with deadly precision.
Also, there's using your weapon to keep your enemies at a distance, thereby enhancing your defense, such as with the Expertise feat. Does it use blind fury? No. Is it more of a cerebral feat? Yes. Does it require concentration? No. It merely requires brains, as is evident by the Intelligence prereqs.
Essentially, fighting doesn't require concentration. It requires that you pay attention to survive, but that's it. There's a big difference between trying to cast a spell and trying to shove your sword into that guy really, really, really frickin' hard.