Agreed, that this is getting out there, my bad for adding to it.
At 25yds I don't think the mechanical accuracy of any gun will be that far different to make any difference unless you are attempting to put bullet holes on top of each other. At 50yds, I think the ability of the barrel to stabilize the bullet starts to come into play. However this is just speculation. Unless someone was to do a controlled experiment (aka exact same guns, bullets/powder/casing/sizing, material of the barrel, etc.) walking targets out to 100yds, in 5-10yd increments, this discussion is academic and has gotten pretty silly.
Practical accuracy is a completely different subject and depends more on the shooter. I think that past experience has shown us that a longer sight radius is easier to aim. Does that make it more accurate? No, but a new shooter would see better groups from a longer sight radius vs. a shorter one, statistically speaking. An experienced shooter with their favorite snubnose/pocketgun would more than likely shoot just as well as a 6" barrel up to a certain distance. However that goes back to the first point of my post which is where we have come to rest.
My apologies for making a blanket statement and adding to this spiral.