Just because you can shoot the qualification doesn't mean its the best gun for you. During the qual nobody is shooting back or trying to take your gun. An officer with a fat double stack grip and short fingers will have a hard time dealing with a real life situation accurately, but with the right smaller grip pistol they are in better control and may have a better pistol for them.
Same thing with caliber.We shoot 40 cal, the department has seem smaller frame shooters have trouble with the round and have now allowed them to carry a 9mm. It goes back to what i said before. One hit from a 380 is better than a million misses from a 45.