I've been to a few of these.
In my opinion, the ratio as it is is fine. About half end up leaving after an hour. One pop and they're satisfied. Apart from that, personally, its nice to be able to take a break from shagging, but still be in the vicinity of it happening. Watching the action (if you want). I reckon there's 3 guys to each girl, but then some girls are more in demand than others and tastes vary. Last time I was there, there were 4 girls. One of them offering anal so there was - literally - a que just for her most of the time. But I didnt find her attractive in the least, so ended up with 2 girls just for me. One even let me cum in her face.
I tend to go with 2 or 3 girls but save my pop for the one I really like. Literally just have sex for the fun of it, dont cum, pull out and let another guy have a go. Then when I'm ready to shoot find the girl I liked the best and finish in her (covered).
Then I take my time with pop 2/3.