Will the RAN make its recommendations to the government purely based on what they perceive to be the best ASW vessel?
That there is even a competition to select a new frigate is not a strong vote of confidence in the Hobart design. Both the type26 and FREMM have stronger claims as ASW platforms then the Hobart class. Navantia may have a lot of convincing to do that they have been able to improve the ASW capability of the F-5000 over what the RAN already knows of the Hobart class.
Not necessarily. Perhaps not even likely. One has to remember that the
Hobart-class AWD's have a specific role of providing for area air defence, much like the previous
Perth-class DDG's and then upgraded
Adelaide-class FFG's had. The frigates(?) to be constructed for SEA 5000 are to replace the
ANZAC-class FFH's, albeit with larger and significantly more capable vessels. The use of the Aegis CMS strongly suggests a much more robust air defence capability than even the upgraded
ANZAC-class frigates kitted out with CEA-FAR and CEA-Mount and up to 32 ESSM. It is also quite likely that the SEA 5000 vessels will have a more robust ASW capability, since the FFH's currently rely upon a hull-mounted sonar and a pair of triple 324 mm LWT tubes, in addition to possibly having a single MH-60R 'Romeo' embarked.
Honestly though, the impression I have gotten paying attention to those with experience in ASW ops makes me think that the ability to have a pair of naval helicopters embarked is more valuable than an acoustically 'quiet' hull. Ideally of course one would want a vessel to be able to embark a pair of naval helicopters, a quality towed sonar array, an acoustically 'quiet' hull, and a quality hull-mounted sonar. However, if fitting all of these features plus the other capabilities desired for the SEA 5000 vessels is not possible, that I strongly suspect that the ASW performance of the hull itself will be considered less important.
Consider for example, how and where the ADFis likely to conduct both offensive and defensive ASW operations. I strongly suspect that whenever and wherever possible, ASW operations are going to be a joint RAAF-RAN effort using airborne, surface, and subsurface assets to detect and drive off, neutralize, or destroy hostile subs in an integrated fashion. As such, the importance would be what specific platforms can bring to the ASW system as a whole would be of greater value than the individual capability of a specific platform. Things have moved on quite a bit since a number of the NATO member-states had their navies start specializing in ASW operations.
What the RAN should be able to do in the coming decade is send a sub or subs into a potential choke point ahead of a task force or high value asset to sanitize the area, and within a number of areas within the region provide support using land-based P-8A Poseidons to create an outer detection/engagement layer. This would then be followed up with an middle detection/engagement layer provided by embarked naval helicopters. The inner layer would be provided by the escorting frigates/destroyers using their onboard and towed sonar arrays and LWT launchers (and ASROC if that enters service). Realistically though, if the plan is to rely upon the screening escorts, then I believe something is wrong with the plan as that would mean the attacking sub has already penetrated two defensive layers and could likely target vessels with heavyweight torpedoes and/or sub-launched AShM's, most likely from outside the engagement range of any ship-based ASW weaponry.