BEFORE the ride choose the pace and stick to it
Remember the goal is to keep the group together, not fragment it.
A Recovery ride of 35kph should be just that
So if a faster Group goes past it should not be a challenge to pursue (we know we can go faster but choose not to)
A Hills Ride should have predetermined regroup points to keep the group together
If your mindset is such that you want to fragment the group and you see the Ride as a personal challenge then you should enter a RACE.