I said yes because it is possible and the long answer would have included the "maybe's" you had already posted.
My lightest capacity shotgun holds 7 plus 1. I have trained with it pretty good although not to competitive levels on the reloads.
My threegun shotgun, a Remington 1100 with 10 shot extension, would be even better, if the space to wield it were available. With this I am extremely confident that only molly maid would be needed when the shooting stopped. Its surprising how fast so many targets can be engaged and eliminated. Even for my relatively small frame.