Whatever they choose for the Long Range rocket platform needs to be armoured truck mounted
Why? Why does something out of range of almost everything need armour? So passive protection a'la the HX77 / Bushmaster sure - but these things can just be a truck.
and under 30 Tonne so 2 can be carried on a C17.
Why do they have to be C-17 deployable? Don't get me wrong, a simple truck mounted system should be (and should be well under 30 t), but making it a need doesn't make sense. I've done the maths elsewhere, but the logistics breaks down quickly if you rely on C-17s. Plus, this is probably a Div Fires platform - the Bde + you are supporting didn't come by air.
Same for the Arty. Land at Austere field and rapidly drive off to position anywhere up to 2-300kms away makes a lot of sense to me especially if we end up with a 300km + LR capability to target ships from MLRS type platform. Or just drive there.
You've hit on it here - the range makes the platform insignificant. The important part of this system is the missile, not the vehicle. Although your artillery comment is questionable....
Yes we need under armour capability but I question why we need something as heavy as a SPG designed for front on battle in the DMZ or Fulda gap.
An SPG needs armour because it's range is much shorter. It will take fire, almost certainly indirect, but still a lot. It needs armour. Furthermore, until we get an autoloader, the crew needs to feed the gun - and anywhere the crew works needs armour. The MLRS doesn't have this issue as the crew don't feed the rockets.
As to why we need an SPG, because it's better than towed in every respect. Towed guns are simply means of killing Australian soldiers in batches of 10.... They give mobility, rate of fire, survivability - all of which is critical to a Land Force.
The enemy in Australian logistics (talking north and Western AU) is distance. The logistics for everything is the same except for fuel and getting the platforms into position where the SPGs will amplify the logistics tail requirements.
Logistics is always the problem. You put 3 or 7 Bde into Shoalwater Bay and logistics is an issue. Even some senior loggies simply don't comprehend the logistic cost of a modern Bde in a modern fight. But.... the SPG has a negligible impact - sort of. There isn't an increased fuel bill, there is a slight (maybe) increase in spares, but they aren't the logistics achilles of artillery. It's the shells. The sheer amount of 155mm that will be required is frightening - and why 26 Transport Sqn exists. The SPG will need more ammo sooner than towed guns - and that's where the problem will be. Having said that though, that's literally just a problem that throwing more trucks at it solves. And we have bucketloads of trucks!
When was the last time the Australian Army conducted a large scale exercise with heavy kit in Northern WA?
At a guess - 98? But - so?
Fighting in the Australian NW is a suckers game. Why would we do that? The bet at work is that if you land a Div in Broome, they have no more than a BG by the time they hit the QLD-NT border. That's before the RAAF and AAvn play.... And between then they have captured - nothing of value....