A lot of great points here.
But right or wrong, when I lead rides I tell everybody that passing whenever and wherever you'd like is fine, as long as it's safe. This applies for passing each other or cages. The scariest thing I repeatedly see when not leading is bikers passing a car just because the bike in front of them did. I watched a so called experienced rider make a terrible pass in NC last spring. I was 2 bikes behind him. The bike in front of him made what I considered a questionable pass as I could see an oncoming car on the horizon. He would certainly make it cleanly, but I felt he was putting undue pressure on the oncoming car and it was simply an asshole move. Then, the "experienced" rider pulled out behind him. I slowed way down waiting for the immenent head on collision. The car literally drove off of the road and into someones yard to avoid our kamakazi rider.
To say I gave him holy hell at our next stop is an understatement. I tried to bring it up respectfully and quietly but then he denied any wrong doing. So I flat out blasted him in front of the entire group, encouring the other witness to confirm the car driving off the road instead of plowing into the biker. He ended up apologizing and asked for another chance. I hesitantly continued on with the group in sweeper position. I knew this guy was trouble before he invited himself into our group and he'd proved it.
About 10 miles later I watched him lowside his Magna at about 15 mph. He panicked in a tight turn, locked up his rear brake and never let go. I suppose it was better than highsiding but the case was closed as far as I was concerned. Our group split from 6 bikes to 3 and 3 from there.
We made nice back at camp. He admitted, again, his mental mistakes. He was riding way over his head. He was excited to be riding with the "faster group" and was all machoed up. That's the kind of shit that gets you dead. I ask riders I'm unfamiliar with to please die on their own time and not in my group.
Vent over as I'm way off topic.