We might just want to clear mines in a war-zone at some point... Having a slow firing un-guided 30mm (for some weird reason instead of a 25mm Bushmaster...) on a small "non combatant" isn't going to do much if there is someone around to actually fire away from themselves and toward us...
The
Huons predate the Typhoon RWS mounting, and I think the design and procurement phase of the MHC slightly predate the Army decision regarding the ASLAV. A requirement was for a locally-operated powered mounting, perhaps the RAN wasn't at the time spoiled for choice of 25mm mounts fitting this requirement?
Mine clearance may need to occur in a combat zone, but it is not envisioned that it would happen without protection from other forces (air or sea). If it needs to happen in a combat zone it would need to be a Priority mission with a capital P and the word underlined twice, so escorts would be a given. During mine clearing operations an MHC is a very vulnerable target, so they shouldn't be left on their own in combat regardless of how heavily armed they are.
Regarding the OCV and weapons, my opinion is that when it is designed/constructed the structure around the forward gun mounting should be made a bit beefier to allow for the
possibility of a different system being mounted in the future (not necessarily a 76mm, a 57mm or 35mm NGS might be more realistic), and the compartment below also allows for the possibility of a mounting intruding below the deck.
I think we're also forgetting that if a more capable weapons system is installed it also needs the associated search and targeting sensors; the limited optical systems of the
Armidales won't cut it. That needs space, weight and even more cash.
Not forgetting that a 57mm or 76mm gun would need a bigger magazine than a 25-35mm gun does.
There has been much analysis regarding RAN needs in the future, and there has been much made of the developing submarine threat across the South Asia-East Asia regions and Australia's vulnerability to military threats/blackmail by attacks on offshore resource platforms and commercial shipping. The DCP has placed more emphasis on A/S capabilities, so it would seem the concern is genuine.
Instead of a corvette bristling with guns and missiles, surely it would more important to the RAN for the OCV to have an A/S sonar, the ability to fit a VDS (not such an issue given the modular nature of the OCV concept), and perhaps even the ability to fire Mk-54 torpedoes via the lightweight, fixed version of the Mk 32 tubes. In such a situation, with cover from higher sea/air assets and operating near or within the EEZ, the 25mm gun and perhaps a Sinbad/Sadral type SAM launcher would be adequate.