I've gotta believe that the longer barrel improves accuracy. Fair assessment?
Actually, the longer slide offers a longer sight radius, the distance between front and rear sights, which in general makes sighting more precise, and quicker for older eyes...such as those of senior officers who get to choose which pistol their service will adopt. That was one reason for the fairly long-barrelled revolvers used for so many years, from the 7½-inch barrelled Colt Single Action revolvers of the post Civil War U.S. Cavalry on forward.