The only issue with your ideas Tick Tock Man is that it’s not a level playing field. When you have a young family and the germ hibernators are in their early years you catch everything going. Pilot’s with young children generally have higher sickness than the folk with no children. Where is the level playing field?
If it has got to the stage that HR have identified pattern sickness (weekends off etc) and you have been warned about it by all means include it in a matrix just as you would disciplinaries.