Never took any 13s along, we always did our own spotting and a few guys were NGF trained which came in handy in the RPI. I have, however, drug a CCT guy along a couple of times...which made me a strong proponent of getting the training ourselves and leaving their 'it's too hot, it's too cold, it's too wet, I'm too tired, my boots are too tight, my batteries are dead' asses back home.
But maybe they're different now.
Richard's $.02