The answer is always - it depends.

Some groups need to stay together, some can split up. The rule I use is that if you step off the trail you need to leave your pack on the trail. It is a bad problem if you are struggling to catch up with someone that is waiting for you, but actually behind you.

Off trail you need a safety bearing. For example if we are separated then hike to the east road and we will meet where it crosses a specific landmark.