Eh. Depends on your "fight philosophy."
Do you intend to gunfight or break contact. Big difference on what you'll prepare for. For gunfighting, you cant have enough ammo, while breaking contact one loaded mag and maybe a back up is enough.
What I mean by those terms is: gunfight, well until one of you drops, and breaking contact forcing the other to flee the scene - main goal is to "chase off" the perp. Not that you'll intentionally miss, but it will happen. And your mission set whatever you choose will dictate your load out. You're not going to try to get into an extended firefight with a 45 and one extra 8rd mag. For context, my micro 9 Hellcat 13+1 nearly the same round count in one mag.
Finally, the whole "plan to miss" argument is really unrealistic. How many of you have been in situations where the bad guy is shooting back. I think it's pretty safe to say that none of us will give Jerry Miculek a run for his money? How many of you have trained for years in a Teir 1 element or higher. Face it, under high duress, the factor of missed shots is a reality.
Case in point, not too long ago a person decided to take out his day on me in the form of road rage. When I actively tried to de-escalate the problem to the point of pulling over to the side of the road to let him pass and go on with his day, he pulled over as well and was going to wait me out. Seeing this that's when the trusty cordless hole puncher was pulled out, and knowing that one was not in the pipe, racked the pistol. Him being in a truck and being able to see into my car saw this and then decided that his poor life choices were going to momentarily stop for that day.
But the first thing in going through my mind was not "I'm hitting his off button," because I know there's kids in the corner house and there's a convenience store close by with non-combatants in it just trying to get their items and gas for the week or day. There's a school and daycare a couple hundred yards away from the corner I was at. You may hit all of your shots, however, can you guarantee that that guy will do the same, which unfortunately, means a bad day for you as well.
In no way am I saying tuck tail. I'm saying that there are elements and consequences that are outside the initial confrontation and as we all know, "a jury of your peers," actually means you're guaranteed a few retards will look you the victim that "won" the encounter as the guilty party because: still alive; ex-breather not armed with a firearm; or a weapon that wasn't seen to be a "threat" in relation to what you chose to carry, ie. he's armed with a 22 revolver and you're armed with a 45 with some edgy named bullets like "Widowmaker," or something implied like "The One Stopper." (fictional round names but you get the idea). This can and most likely will be a tick against you if you get some progressive assistant DA looking to run for mayor.
I developed a personal rule which supersedes all gun safety rules. "When you exercise your 2A right, you lose the right to be emotional and or lose your temper." However, please don't take this as some sort of "I'm better than you," opinion. I absolutely am not.
I hope you all live in peace and good health.