That is more what I'm thinking of, not on a weekend trip in rough country.
Although it does work out that way sometimes with people leaving early or alternate route past a hard bit etc.
Now you know how some spend their weekends there is an opportunity to make it very clear when you plan to get moving.
My technique with stops is point out loo's or servo's if available, and watch when cups are getting empty with a call of "saddle up" to get every one back in their cars. Give them a couple of minutes and drive off slowly calling for tail-end-charly to sing out when he is on the move. Never had an issue except one micro managing trip leader, never been on a trip he has led since!
Works for me!