Unfortunately no one does this. Or at least not the two airlines I've flown recently. They board the first-class passengers first, then all their special clubs (Gold Members, Sapphire Members, etc), then they board by groups. I can't really identify what makes you a Group 1 vs a Group 4 member, but I don't think it's based on seat assignment. On the last four flights I was on, I spent five minutes standing in the aisle, trying to get to my seat at the back of the plane but blocked by a dozen people in various rows trying to put their luggage in the overhead bins. From the time the airline started boarding to the time they shut the cabin door was anywhere between 30-40 minutes each flight. Getting off the plane, by contrast, took about 15 minutes.