You should pull at the pace the group is going unless you want to PURPOSEFULLY increase the pace. As in the have a REASON.

The faster the pace the shorter the pulls. Some workhorses will take monster pulls which only makes sense if they truly are that much stronger than the rest of the group.

A typical fast pace line means 20 pedal strokes in the wind and then rotate back. If it is a medium tempo then the time can very quite a bit.

Guys who can't pull through should NOT rotate with the group but should sit in the back and leave a bike length gap for people dropping back to slide into the line. People eating should also do this. No-one but a n00wb should have a problem with this.

The trick is communication. Most of this is non-verbal. Your actions should clearly signal your intentions. If they don't, or people are having trouble figuring out what you want to do speak up. Keep it to less than five words.

If the group you ride with hasn't figured this out yet find another group.