I believe that typically there should be no issue with anyone joining us (any groups in CS) for the shoot. Should it gets a little trickier, just pre-alert the organiser a little prior to the event and most shooters will be willing to be of assistance. My shooters buddies do look after one another in the team... anyway.
welllll you see
it's very useful when you sleep at night
and if you don't really want to listen to someone talk, you can just walk on their right side.. and after a while they will realise that you can't really hear them