I just saw a documentary on the notorious Satanic Serial Killer, the Night Stalker. In some of his break-in killings, the Night Stalker was able to shoot and kill people in the dead of night or super early (quite before the crack of dawn) in the morning, and some of Night Stalker's victims even tried grabbing their own personal firearms, but it was too late and Night Stalker shot them dead anyway, showing that just because you have firearms in your house, doesn't mean your invincible, especially if it's someone totally evil like Nightstalker who just wants to kill and main you and your family's corpses and take your belongings that could sell for quite a bit.
Now granted, calling the cops would leave you even more helpless in that situation and I'm not suggesting giving up firearms, but I'm just pointing out how you aren't invincible from evil psychos who may break-in at the dead of night if you are a trained owner of firearms. What if some evil guy out for blood breaks in and he also has a gun? Wouldn't the fact that such an intruder has a firearm too take away your advantage?
The key is a properly hardened home giving you reaction time.
Initiative counts. There's a reason ambushes are useful tactics between two armed forces.
The 2A only guarantees you the tools necessary to protect yourself. It is up to the person to train, and everybody should train.
"it is better to be a warrior in a garden than a gardener in a war."
What is your point? Breaking in makes noise and in the majority of cases will give a person time to arm and respond. The stalker was a different type.
I would research, did they have canine alarms?
I have three that go ballistic when there is noise at one of the doors. They make different barks when a squirrel walks by.
I hear their alert and the gun is out and ready.
Regarding advantage, having a gun evens the odds. Dialing 911 is a loss.