My understanding is that the next project after the AWD's at ASC is the Collins replacement. I cant see ASC being in the running for the Anzac II's. Also I always imagined that Austal might be a starter for the OPC's.
What you suggest sort of illustrates the problem. If a yard other than ASC is the prime for the Anzac II, that would leave the Anzac II to be built by BAE at either Williamstown or Henderson, or Thales Australia might be able to setup a facility to launch frigates, or perhaps Forgacs. Unfortunately of these, only Williamstown has had recent work building naval vessels, but since the Anzac II programme is likely not being stood up until 2020-ish, then the yard would be an 'inexperienced' one, in that they will not have performed the lead functions in 15+ years.
All the experience which the ASC yard & workforce would have built up during production of the AWD's would not be working on the Anzac II. This would be IMO an even greater issue if the Anzac II hull is indeed based off the AWD, but with a different superstructure and fitout, as ASC would have even more experience with such a hullform.
As for the OPC going to Austal, do you mean the OCV? The OPC was to have been a 1990's programme where Tenix would construct OPV's to replace the FCPB's IIRC, which got delayed then cancelled with Austal being awarded a contract to build the ACPB's as the Fremantle replacement. Personally, I hope Austal does not get the OCV contract, as that would IMO be contrary to the best interests of the RAN and the Commonwealth. Austal specializes in and does very good work with aluminum multi-hull vessels. They can build mono-hulls (like the
Bay-class and
Armidale-class patrol boats...) but they still work with aluminum. Not only is aluminum more expensive to work with for marine construction, it lacks the fatigue life of mild steel. That is part of why the ACPB will need to be replaced after ~15-20 years.
If people were also to suggest an Austal design like the MRV 80 be put up as an OCV... Such a design as is, is IMO quite unsuitable for the RAN needs. This has come up a few times before, but such a shallow draught, aluminum multi-hull is built to HSC standards, which means that needs to remain within ~8 hours sailing time to a port. That would allow the class to patrol portions of the EEZ in and around mainland Australia, but would likely put Cocos (Keeling) Island and Christmas Island out of reach, nevermind Heard & McDonald Islands.
I suspect that even if the design were redone but in steel, it would still be unsuitable based off performance. Mult-hulls AFAIK are good at maximizing internal volume relative to draught and displacement, but that comes at the cost of max total displacement. Further, due to the dimensions above the waterline the vessel's seaworthiness in high sea states can be rather poor. Going with an Austal design again would likely restrict the OCV to operating along Australia's north shelf, and would likely not permit an OCV to accompany a RAN/allied task force to either provide littoral support, MCM or survey work.
-Cheers