The white paper is cleart that the M113 upgrade is a short term stop gap until the replacement is ready. LAND 400 Phase 1 had an in-service delivery of 2015 to 2017; presumably the M113AS3/4s were scheduled to be on the back end of that.
This white paper is a complete overhaul of defence thinking and strategy, it is possible that additional resources could be availble over previously established procurement plans and budgets.
I don't expect the ASLAV upgrade program Land 112 Phase 4 will go ahead.
I am no expert on numbers needed, presumably the minimum requirement of IFVs would be enough to equip the two cavalry regiments and the two mechanised battalions (plus spares for maint/training etc) - How many would be needed for that? perhaps 430?
Cost-wise: the VBCI (for example) reportedly costs around US$3.8m ea, so 430 similar IFVs for the ADF would cost around US$1630; this is somewhat more than the $1750m (max) already budgeted for Land400(ph1) and Land112(ph4), but seems feasible.
Maybe the shortfall (220 vehicles) could be comprised of Bushmaster support variants?
Originally the LAND400 was intended as a replacement for the M113 and ASLAV vehicles. This was before Bushmaster emerged. Later the Bushmaster was included in the numbers of vehicles to be replaced by the LAND400 design, but this was before Bushmaster became the most numerous armoured vehicle in the Army parks.
Consequently Bushmaster is no longer the support vehicle to the M113, and the amount of money spent on the M113AS3/4 upgrades means that the Government, at least Labour, decided to get their money's worth out of them.
Hence why the White Paper is not saying "IFV" but a "protected vehicle", which can mean just about anything, and leaves much to speculation, but at least no one will be able to call the Government liers since the M113AS3/4, the Bushmaster and even the armoured trucks that will come as the Landrover replacements are all "protected".
There is a complete overhaul of defence thinking and strategy, but it seems to me unlikely there is a possibility that additional resources could be available over previously established procurement plans and budgets, primarily due to the coming budget which, to quote the Treasurer, "is going to be unpopular".
Presumably the minimum requirement in IFVs would be enough to equip the two cavalry regiments and the two mechanised battalions (plus spares for maint/training etc), but the Army will tailor its organisation to what is available as it always had before. The absolute minimum for the mechanised infantry battalion is the Soviet model of about 40, and a maximum is perhaps as many as 60 sharing same chassis. Clearly under my assumptions a one-for-one replacement of ASLAVs is not feasible, so not sure what would happen with the recon regiments.
The original LAND400 budget was in the AU$1 to 1.5 billion mark. However, this is the project budget and not one based on unit cost only. That is the spares, introduction into service, and all other sundries also come out of this, which is why not much has been heard from that office in the last 3-4 years. The Army is saving all the money for the final purchase.
Almost anything is possible in the ADF it seems. If the Navy reckons they can crew 12 submarines at the same time, maybe the Bushmasters can become support vehicles to IFV-equipped armoured infantry units, and that is what they are called in the British Army where they are equipped with the Warriors.
Probably the two armoured infantry battalions will rotate for service on the LHDs, with elements of one being combined with a mechanised (M113AS3/4), motorised (Bushmaster) or light infantry battalion providing backup as required by the situation.
Note the White Paper is subtitled Force 2030. If the LAND 400 Phase 1 has an in-service delivery of 2015 to 2017 (it had the 2012 timetable before), then in reality it will be 2020 before there is a first upgrade due to be carried out because anything available now will be hopelessly outdated by then, and by that time it will be time to replace the M113AS3/4s also, probably not by the Labour Government's impending 4th term, so that is when the rest of the LAND400 vehicles will be purchased. Probably (speculating) the Army figures they will get well over 40 years service out of the M113 hulls, so they might as well get something that will last 60 years with the LAND400.