I think it depends on your defensive strategy. Where are the bad guys likely to enter? Where are you likely to be when you have detected them? Is the AR going to be at hand at that point? Are you going to attempt house clearing? Home defense, more so that street defense, is one arena where I think you have a decent idea of what the scenario might be.
For me, the bad guys will certainly come in the ground floor. My second floor windows are just too inaccessible. The alarm will go off on entry and the dogs will bark. I have my EDC on my nightstand and a .357 in a push button safe under the bed. The EDC will go in my pocket and I will be using the .357 as primary. I do not intend to go downstairs. I plan to clear the hallway and take up a defensive position at the top of the stairs. I will go with the two handguns, because they maneuver around corners better and they are handy to grab. I would only go to the riot shotgun if I was expecting a mob, which could happen nowadays. But in that scenario, I would already be awake and dressed.
I'm not suggesting my solution should be anyone else's. I am suggesting everyone think through possible scenarios and reactions like I have.