Thanks for replying, boomer! Have been super-busy since posting and haven't had time to come back to this to post something thoughtful.
A quickie I wanted to put here though (until such time as I CAN post something thoughtful...) Yesterday sozlet had three friends over, all girls. They did this and that and a while into things they started wrestling in the living room. I was worried about them cracking their heads against various pointy parts of the room and so sent them outside. They then wrestled for the next half hour or so, in pairs. One pair would go at each other while the other pair acted as refs/ commentators.
They were really going all-out -- there were rules against hair-pulling, eye-gouging, and tickling, but otherwise pretty much anything went. (I usually let them do their thing and don't pay much attention but they were really whaling on each other so I wanted to keep an eye on things, both to put a stop to it if it seemed to get out of hand and so I would know what happened for after-the-fact disentangling [who did what to whom], if something did go wrong.) As they tussled, I thought "girls will be girls" and then thought of this thread.
(No injuries, thank goodness, though one girl burst into tears when pinned. Overall everyone had a great time.)