Australia's Mogami choice and the rule of four

What should be made of Australia's improved Mogami-class order?

It is a sensible lower-tier complement to Type 26-level ships, provided Australia buys enough hulls to support a rule-of-four rather than another fragile pair.

Either an improved Mogami or Type 31-level design would be a sensible companion to Australia's higher-end Type 26 force. The more important problem is quantity: Australia has often bought pairs when sustainable operations demand at least three ships for one continuously useful commitment. A rule of three may support the wartime operational cycle, but peacetime presence, naval diplomacy, and conventional deterrence need additional slack. Planning closer to a rule of four or five would provide that margin. The individual frigate choice therefore depends on the less visible arithmetic of maintenance, training, and deployments.