Answering my own question:
My understanding is that six people from each team need to be in each arc at each centre bounce. This means that you can’t put an extra behind the ball (woot we might beat carlton) and it also means that you can’t run off the square at the centre bounce.
It should mean that the four centremen and the wingers have a relatively free run at it, although on grounds like the SCG that are shorter it will be less noticeable as the fifty meter line and the centre square are very close.
What does that mean?
I think that the star mids who can clear the ball and can burst out from the stoppage will be the most critical players in the game (if they weren’t already). Think Judd, Josh Kelly, Dusty, etc
Ruckmen who can play as an extra mid in the Brody Grundy mould and great tap ruckmen like Gawn will rise in importance.
I assume the wingmen will become more critical- rather than outside runners who cover lots of ground they will be important for either running the ball out or keeping the ball in.
The pacy half backs who run through the contest at the moment will have to run further and faster to impact the contest. The ground is going to be less congested so I wonder if that manic run off half back is going to be as important a weapon. Foot skills in the backline might be more important than pace.
Forwards should get more one on One opportunities so marking forwards and stingy defenders who win 1:1s are important. Can’t rely on a third man as much anymore.
Also defenders with big engines who can run fast enough and cover enough ground to form the defensive strategy asked of by the coach once the ball is bounced.
Feels like our list is ok with the exception of those genuine gun clearance players in the midfield. Richmond and Melbourne seem really well prepared with lots of hard ball winners and tall forwards who can win 1:1s.
Lots of hypotheticals, interested in others thoughts