Here's a naive question from a new golfer: Why can't you trot up to the slow group and say, "Hey man, my group is playing faster than you guys. Do you mind letting us play through at the next hole?"
If they say yes, you win. If they say no, you call the clubhouse and say there are slow-playing idiots on the course. If the staff does nothing at that point, they've shown they have poor customer service skills and you take your business someplace else. In any event, you pretty much win. Right?