In a true life threating attack on your person it can be a valid life saver.
Trained professionals fail to put the majority of shots on target most of the time. There are too many variables to account for in a gun fight to say any one technique is right or wrong. Any advantage you can initiate is to your good. Training, mind set and determination to live will be your best friend.
Others have employed the string technique and I have practiced it myself with a modification. Using a silhouette target I commence firing from the low ready position at the groin and work up to the head with rapid fire. I don't wait till I'm sighted on COM ... That could be too late. Of course, shooting at someones feet
could get them to dancing in the other direction.
Real world ... with a large capacity pistol stringing your shots
might just save your life.
Not to be adversarial, but it is suppressive fire. That's right ... Your goal is to suppress the attacker before he suppresses you!