I am not sure there is a need for a rotation. Many people have only 1 or 2 straights (I guess that is sort of a rotation). Also, most people would strop their razors right before they shave so I would not think that is the reason either. Not sure that buying more razors, as much as having variety in your shaves, is what drives most folks to have a rotation. Many people that own many razors do not use a rotation. Some people find one razor that is sharp and stick with it until is dull and then hone or switch. I have a few razor but not always use them in a rotation. Some days I feel like shaving with the same razor I shaved with the day before.... I guess everybody is different.

Al raz.