You do need to aim a shotgun -- sort of. But if it fits, and you've practiced or hunted with a shotgun a lot, you can shoulder and point it really quickly. Here's a hint: rifle sights make this SLOWER not faster.
The idea of a shotgun that fits is that you can shoulder it and you will be looking down the barrel. Point it by moving your upper body as a unit, and you can acquire and hit just about anything, even something moving, quickly. Note that upland bird shotguns have a bead, or maybe a rib and bead or two beads so you can confirm that you've shouldered it straight. They don't have ghost rings!