Even though AFL is demanding, it was still unusual for a team to make that many changes on a regular basis and to rest those who needed a break during the season like they did. Many would have considered that "flirting with form", if they knew that was Geelong's plan for the year, just the same as they would consider resting someone like Siddle (who has played 8 tests in a row and looked buggered at times in the Perth test) "flirting with form".
I heard on the TV, or whatever, the other day, that the likes of Siddle are covering something like 25kms per innings (from GPS measurements) so they are doing a lot and that is every couple of days during a match, not once a week, as it is in the AFL.
I see very little difference between what Geelong did and what is being spoken about with regards to us rotating the fast bowling stocks, if they need it ("if you need it" is the key, whether it's Aussie Rules or cricket, or whatever.).
As for the 3.3, that is what I heard in the media after the season/during the finals, may have been on one of the Foxtel Footy shows. They said that Geelong averaged approx 3.3 changes to their team per week for the season. Maybe they got it wrong, but that's what they said.