At 5-6 feet, Jelly Bryce took a 1/2 side step and shot a BG bringing a firearm to bear on his person, upon entering a hotel room. Thing is, the BG didn't get a shot off before he's been head shot, so his 1/2 side step wasn't what gave him the edge in that encounter, it was his hand/draw speed.
At other times, Bryce crouched and used stand and deliver to dispatch many a BG in gun battles [ the majority of times from the accounts that have been written about ].
As I mentioned earlier, the mentors [ a former OSS officer trained in WW2 handgun skills ] had more experience in actual battles with handguns than most I've run into. His feelings and advise was to get the gun operational and get down to business without dancing around.
Hence the reason to train both stand and deliver and move while shooting skills. Movement for the sake of movement at every encounter isn't necessary or wise, nor is stand and deliver the winning game plan all the time. Make the wrong choice at the wrong time, you're in trouble.