Good point. I've seen our Canada geese flying in W's and sort of W's as well. It's not like there needs to be only one lead. It's just that the stronger or best rested gets to the front to aid the rest in making the journey.

Also to add to an earlier post about why this is different from airliners avoiding each others wake. When it's done like this where the following goose is "in the zone" it's sort of like a kayaker that is surfing on a standing wave in a river. He's getting a free ride which is what the trailing geese are doing. But if the trailing line falls back a hair then much like the kayaker in the standing river wave that falls off the front or to one side the gain is gone and they are on their own. Which explains why the V's can be seen constantly forming together and breaking up.