I'm questioning the real world scenario where will we need to use the LHDs to perform a hot landing within a AWD envelope.
It doesn't have to be a hot landing. If we want any US assets (cruisers, destroyers, subs, amphibious, carriers) to help us, we have to provide adequate screening for them. The screening requirements were set by the US, not just to our local threat. Of course we could have tried it without US support, but we wouldn't have gotten any real traction. What nation would join us if the US wasn't on board?
The US plays in a global game. It sets its requirements. Giving exceptions to Australia doesn't make working with its allies easy globally. If they went in without screening, then every other nation in Africa, middle east, europe, asia would have been demanding US deploy assets in a similar situation, alliances could be placed at risk. Gateway to global instability.
While an Australian ship in Australian or international waters is unlikely to be attacked, the US is in a very different situation. So even in a peaceful straightforward mission, there requirements are just very different from ours, they can lose ships tied up in a friendly port. Any time a US ship sails, there may be half a dozen assets from other nations following, collecting intel, ready to make a surprise gesture (chinese submarine surfacing in/near US carrier groups etc. Heck if its North Korean they might just make a suicidal gesture.
This is why we have to be capable and independent of the US. Not to act without them, but to act with them, even on our door step. The US can't act on its own morally, but can't act with us because of the global implications. They aren't a mercenary force we can just call and have them turn up, even if we are directly threatend.
It's as I said before people focus on the platform first and then try to twist capability out of them instead of looking to see what capability we'll need and then designing a fleet around that.
Its more complicated than that. This is why we need PAC-3 (not really SM-3, but we are upgradable to that), SM-6, TLAM and wizbang AWD's. Not to fight off indonesia, but to be able to work with US forces to be part of the larger picture. Eg. Any time you deploy/train around Korea (or Japan or anywhere in Asia now) with US forces, your at risk of having a very serious missile head your way. Whats the alternative? Tear up our relationship with the US?
There is no real reason why we can't afford 4 AWD's and 3 LHD's. I do agree a lot of people get caught up on platforms (on forums on in some countries procurement). We need this platform and it solves all our problems (F-111/SU-30/F-22?). But I don't think the RAN/ADF is heading that way. The AWD isn't a deathstar fortress, its a very capable ship for a mid level navy. We have already purchased 3, and have an option for a 4th. We have already purchased 2 LHD's, and could easily option a 3rd from the supplier (possibly partly funded out of euro aid).
But its driven by what we want to do rather than just the platform. Which is why we got F-100's rather than Burkes (part of a bigger discussion).