Like just plain old shove a round in a tube or like Dragonfire type mortars (which would be excellent for RAR btw)?
I think thats pathetic hope we don't get drawn into a major conflict anytime soon... at the very least they could get some 120's...
Yes, but the training requirements are the issue, not the capability.
The drills (and more to the point the interaction with FO parties aka JOST teams) for "punching bombs down range" are what is important, not so much what type of "bomb is punched".
Individual artillery skills can be learned very quickly. Indeed the IET course is only 4 weeks or so nowadays for regular artillerymen.
Collective capability as a battery is what is needed, not skills on a particular weapon system.
This is why the M113 and 105mm guns are being withdrawn from reserve units. It's not the case that reserves "can't" learn how to use modern equipment, but rather that the skills needed to do so aren't so difficult to acquire, but the training benefit from attempting to do so with limited training time available isn't deemed worth it.
Effectively you have a reserve unit operating modern equipment at a level significantly lower than regular units (due to more limited training time) and a capability significantly reduced due to reduced collective training opportuniities. The cost to maintain said equipment remains the same, for significantly less "quantifiable outputs".
Learning to operate as a basic soldier and as a unit is deemed to be more beneficial in the current era. If a soldier or a battery needs to be qualified on a particular system in the event of major war, they will be trained to do so and will benefit from the increased training put into individual and collective activites, moreso than increased maintenance and training focused on "high tech" (aka: complex) equipment.
The basic ability to function as an individual soldier and as a unit will be improved and the ability to operate specific systems can be learnt as required for particular taskings...