Todjaeger
Potstirrer
Another potential way to look at it is that of three vessels, at any given time one would be undergoing maintenance, the second would be undergoing training and workups, and the third would be available for deployment, with a potential surge capability of one of the other vessels as well.With 3 ships 1 should be available all the time and 2 some of the time.
With 4 ships 1 should be available all the time and 2 most of the time.
With four vessels instead of three, the typically one would be in maintenance, a second undergoing training, the third could be deployed, with the fourth available for deployment, and then a potential surge capability of an additional vessel as well.
Some of this depends on the expected maintenance cycles, as well as just how often the AWD's are going to be deployed 'away from home' as it were. While I could be mistaken, I suspect one of the major roles the AWD's are expected to have is to provide escort and air defence for the fatships. I would therefore expect that the AWD's are not going to be deployed far from Australian shores, unless they are escorting other vessels (like the fatships). I base this suspicion on just the limited number of hulls currently planned for area air defence within the RAN. The more GP nature of the upgraded Anzac-class FFH and whatever will replace they are more apt to be deployed on their own. Not that the AWD's would not be capable of independent operations, just IMO they are capable of acting as escorts in ways which the FFH's cannot.
-Cheers