I think the general consensus of "high capacity" is more than 10+1
No. I think High capacity in a home defense 9mm is over 15 or 17. On an an AR it be anything would be over the standard 30.
It is the defender, the person responding in surprise to someone else's planning and threat, who needs the rounds.
it is also the person who needs to defend unarmed third parties (their family members) who needs the extra rounds.
My wife, with minimal training, could Mozambique a paper target consistently. Frankly it is stunning given she never handled a weapon of any kind until last year. But that has next to nothing to do with what will happen if she is home with the kids and someone starts kicking down the door waking her from a sound sleep. frankly I am a decent shot too, and it also has nothing to do with my capabilities in that high stress surprised situation either.
I think there have been reviews of high quality simulations of stressful live fire by professional law enforcing where they consistently empty their guns and have no idea what their shot count is.
For home defense in a full frame pistol, 15 or 17 is not overkill and 10 round could very well be low capacity.
The school other spree killings in the news, although marginal outlier events in terms of overall gun violence and murder, are being used to argue for limiting capacity. These people are already suicidal, and they pick the softest target on earth. they pick places were victims are trapped and dense. No one with any knowledge can assert mortality of their victims would be less if the killers had 45 cal 1911's with 10 round mags and 20 or 30 mags. The advantage higher capacity affords is against another armed opponent, and these guys NEVER face one.
IN my case, because of the discussion of new gun controls, I did go off the fence and bought a standard full frame 9mm (currently with 10 but normally used with 15 round mags) pistol for my wife. I had learned, like a good deal of us, that assigning her a the 5-shot 38-special revolver was basically my prejudice, and that after some practice she was much more comfortable with a semi-auto.
in a home defense situation the difference between 10 and 15 could be life or death.
You are acting as a proxy for the police. It is simple why is the patrolman's "standard" capacity 15 to 17?