You are still basing your assumptions around a single task force with the capability based onthe helo carrier any the expense of more capable escort. It is unlikely that we will be able to confine ourselves to a single escort task. If we have a single carrier with the majority of aviation assets then you are denuding the layered defence and removing aviation from other escort duties.
Reducing the number of escorts to have a helo carrier when we have two LHD and a mirage of other aviation capable ships is a poor return. On investment. As noted before we need a broader escort capability and, if anything, more aviation assets to operate of the escorts, LHD, AOR and LSD-A.
Where it really would have worked is back in the 80s when we had the Sea Kings that all of a sudden couldn't get to sea except on Stalwart and Tobruk, then Success, which in turn hobbled Ikara which relied on data fed from the Sea Kings dipping sonar to be used to best effect. We had high end ASW helicopters and ASW missiles in service that were rendered useless, and a surface fleet, suddenly lacking the Skyhawks, Trackers and large ASW helos that was left virtually defnecelss except when operating with allied carriers.
Only the six FFGs would eventually (almost a decade later) be capable of independent operations following the arrival of the Seahawks, though they were still markedly inferior to the DDGs with their lack of a 3D radar, even post FFGUP. The DDGs suffered from their lack of an organic helicopter, meaning they needed to operate with FFGs or allied ships so equipped to be able to adequately defend themselves, let alone be effective, while the River Class frigates, which also lost their Seacat missiles devolved into little more than patrol frigates / gunboats.
In fact after the loss of the carrier things got worse when the DDGs with their 3D radars and valuable command and control facilities were retired without replacement meant that even following the introduction of Seahawk and SM-2, it wasn't until ASMD started to roll out and more recently Romeo entering service that the RAN has begun to claw back some of its comparative capability.
Its not so much the things you can see that makes the difference, its the systems the layman is often completely unaware of that are critical to capability. SM-2 is little more than a longer range SM-1 without a 3D radar, and is very platform reliant for the best performance, Ikara without a dipping sonar was just a torpedo sling and we may as well have just had ASROC. A small carrier, preferably three of them, or even a similar number of Shirane type DDH or even just buying frigates that could operate Sea Kings would have helped, i.e. buying half a dozen later Batch II or Batch III Type 22s from the UK, but instead we spent a decade with the RANs sole ASW capability was ship launched light torpedos an hull mounted sonars.
To put it in context, imagine the RAAF was forced to accept Hornets with ballast instead of radars, or the army had to wait a decade between the retirement of the Centurion and the service entry of the Leopard (or maybe an M-113 with a 90mm gun would be a better analogy), maybe forcing them to retire their SLRs and M-60 GPMGs in the early 80s and having to use upgraded Lee Enfields and Owens until the Styers and Minimis arrived would be a better comparison. Though thinking on it, my understanding is by the mid to late 70s the AIM-9B used by the RAAFs Mirages were inoperable and the aging 30mm ammunition for their cannons was likely to explode on being fired, making the type effectively useless through until the Matra magic missiles were incorporated in the mid 80s. Also the army was actually forced to reintroduce 106mm recoilless rifles to the battalions after the retirement of Milan.