Then of course there is no reason why we would need to build 8 or 9 more ships based on the F105.
We could just build a couple of more Hobarts and give ourselves more time to evaluate the Type 26 and other contenders that aren't in the water yet. In fact that would seem to be the lowest risk option.
Having said that I do like the Meko A400.
Yes exactly, up until we decided to go cheap with the FFG-7 we maintained a mix of roughly equal numbers of multirole destroyers and ASW frigates / destroyer escorts. In fact the FFG buy was part of an attempt to replace older GP destroyers and ASW destroyer escorts with a GP guided missile frigate, i.e. instead of six destroyers and six frigates (specifically in the 70s 3DDG, 3DD, 6DE), it was to change to 3DDG and 10FFG (all of this was with a carrier in the mix).
Once we got out of the carrier business plans changed and a low end was reintroduced but numbers were planned to increase from six destroyers and six frigates to eight guided missile destroyers / frigates (DDG/FFG) and eight patrol frigates (FFH) planned with 3DDG, 6FFG and 8FFH, with the first DDG being replaced by the final FFH before a new class of 6 FFGs began replacing the remaining pair of DDGs and the first 4 FFGs, with the final pair of FFGs (which were a decade younger than the others) being modernised.
These major surface combatants were to be supported by eight to twelve OPCs, basically light frigates or corvettes, to replace the Fremantleclass PBs. They would be armed with ESSM (Mk-41), a 57mm SAK2, Harpoon and perhaps most importantly a light/medium naval helicopter with modern anti shipping missiles or ASW torpedoes. This was actually an old concept that the RAN had been trying to get off the ground since the late 50s, they were a modern incarnation of the prewar/ wartime sloops, corvettes and frigates (some of which served into the late 50s, early 60s. They were general purpose warships that were second rate ASW, gunnery, anti aircraft as opposed to frigates that tended to be first rate at one job and third rate or totally lacking at the others, or destroyers that were first rate at all jobs.
Of couse none of this went to plan and primarily to save money (but also to increase the size of the F-111 force), the Keating government decided to defer the DDG/FFG replacement, retire the DDGs and upgrade all six FFGs. This would have reduced numbers of major combatants from sixteen to fourteen but wasn't seen as a major issue with the OPCs brought forward and due to follow the ANZACs out of Williamstown.
Then there was a change of government which saw the OPC cancelled, the FFG upgrade awarded to ADI, instead of Tenix (who had built them), leaving Williamstown with no RAN work whatsoever to allow them to maintain what was at the time the premier naval shipbuilding workforce in the Southern Hemisphere. This basically pissed away a capability that had taken almost two decades and hundreds of millions to build. ADIs selection to upgrade the FFGs had a number of effects, it increased "greased" the sale of ADI to Thales, it saw the RAN getting an inferior upgrade baseline as the Tenix plan was far more comprehensive, and it saw costs blow out and schedules slip as ADI lacked sufficient capability to deliver. In the end only four of the six ships were upgraded at much higher cost and more time than it would have taken to build either six new FFGs or three Arliegh Burkes at Williamstown.
A very verbose way of saying six AWDs and six ASW frigates would have been closer to traditional RAN force levels than the current and planned levels (since the first three FFGs started retiring without replacement due to botched upgrade and replacements programs). A second batch of three AWDs, even at the expense of some ANZAC replacements is probably worth it.