The idea of 'staggered' riding is to present a LARGER picture of people riding to other vehicles and to prevent vehicles from "entering" the formation of bikes. Nothing holds a rider to a set position during the 'whole' ride ... the rider has the option, to move to the side, to avoid a hazard. And we all know that in a curve, a rider "tends" to form his/her own line through the curve, maintaining a 'staggered' formation does not quite work well here.
Here is what I learned and I ride by:
There are three riding positions within your lane
Position 1: The left tire track of a car. This is the home position, the place to be on straight roads. While in the right lane of a four lane highway to claim your lane. On a single lane road, setting up for a right hand corner to give you the best line of sight being observant of oncoming vehicles crowding the center line.
Position 2: Center of the lane. Mainly when approaching a blind hill crest to be prepared for what is ahead, called the "dead zone". Also when riding in the center lane of a six or more lane highway.
Position 3: The right tire track of a car. While in the left lane of a four lane highway. When passing you stay in the side view mirror of traffic to your right until ready to pass, then move to the center of your lane and pass in a couple seconds, especially when passing a tractor trailer, do not linger beside any vehicle if possible. Also, when setting up for a left hand corner for the best view down the road going into and through the corner.
These are not hard and fast techniques, but what I learned and practice on every ride. Every road, stop sign/traffic signal, and corner offer up different scenarios, riding experience and personal safety dictate your decisions! Ride safe. BB