Groups of 3 at each of the 6 central stations. 2 players in each goalsquare. Depending on numbers, you can optionally remove 1 player from the goalsquare at each end (no F3 or F4); also you may leave out group (C4) and have (C2) work both ways. Extras spread between crumbing stations (C1 to C4).
(F1) kicks to non-leading group of 3 at (M1) who contest the mark. Optionally you may make this a 2-on-1 situation (hand out an opposition strip)
(M1) compete in the air, then handball to a runner from (C1) if a mark is taken, or spoil the ball to stop their opponent from marking, or block for their teammate if 2-on-1
Once the ball spills to the ground, (M1) players stop competing immediately and allow (C1) to gather.
(C1) must judge the flight and predict the likely drop-zone or place to receive
(C1) receiver steadies then kicks to (M2) threesome for the next marking contest.
(C1) then join (C2) - all crumbers move to the next crumbing station
(M1) stay put - as does the other marking three (M2) once they compete
(M2) competes as per (M1) and (C2) get front and square as per (C1)
(C2) receiver steadies then kicks to leading (F2).
If (F3) is active they restart with a kick-out while (F2) takes a set shot, otherwise (F2) returns to the goalsquare to kick-out to (M2)
Going back the other way, (C3) and (C4) become crumbers for the same marking players at (M2) and (M1) respectively
Although the diagram demonstrates a circular pattern of play, (C1 to C3) can receive left or right of (M1) and (M2)
Optionally change the marking players after several minutes
