Were the people playing all from the same household?
It was House Baratheon on one side and House Lannister on the other so perfectly fine.
I very much doubt it. All young adult men.
It does beg the question of the nonsense of a general interpretation of the rule for all sports. In tennis I've never seen two players only 75cm from the same part of the net at the same time. Possibly in doubles, but they wouldn't be allowed anyway.
When I'm riding with other people (not often, I'm mostly solo), it's never two abreast.
The rule has changed - now it's just any two people, so I can ride with Noel again, and Liam can thrash someone else, not just you. (Assuming tennis courts don'r go the way of golf courses.)
Subiaco court is closed now but I did see people playing on the Onslow Park courts.