Haymaker
This
If 3 full-timers call a 3 day strike, the company loses 9 man days
is true in an environment where everyone works every working day.
But it seems to me it is all about crewing planes, not about productivity in an office environment. If you don't have enough crew to despatch legally, the flight must be canceled.
So if you are one down, it does not matter whether they are FTE or 33%, the effect is the same, the flight is cancelled.