A friend and I run a match and have played with this as well. We have 14 slots at our matches currently. The last match we had 7 people on my squad everyone shooting two. One guy didn't show and another is an elderly guy who can not paint / pad etc. This leaves 5 people to do things. One shooting, one pad, one timer, one reloading and one painting. It really becomes stressful in my opinion. I don't really believe that rimfire/ centerfire makes much a difference but the multiple guns do. For reference we get though 6stages in about 3.5 / 4 hrs. This is a typical match. We had an 8 stage last month, one gun 10 per squad. It took about 4.5 / 4.75 hrs. The match was run about as fast as they could no asking people to paint or wait for people at the line. I think this is about our natural pace around here.
As a side note we reset stages after a squad runs though. We only have two bays. This takes about 3 to 5 minutes to change. All pre market and ready to move.