Well I was a light infantry guy so I'm out of my lane when it comes to armoured doctrine. But I guess that such AFV would be an interesting "rich men's" artillery for IDF and DF support at a relative low organisational level. While it would be certainly wise to employ them carefully and well to the rear in high-intensity combat they should be able prove their mettle against most threads with decent passive protection, an active protection system and the addition of HEAT-MP rounds. A remote-controlled weapon station (GMG, .50, GPMG) with a well-rounded sensor package could provide the so valuable hunter-killer ability in direct fire fights. Pricey but worth it IMHO.
I am totally d'accord with you that such a system is defenitely adding alot of usefull capabilities. As I said before such mortars should be incorporated at Bn level. Why the Bundeswehr eliminated the mortar units of the PzGren Bns is totally beyond me and I hope they correct this better sooner than later.
As for protection and self defense.
I would also use an IFV chassis (CV90, Ulan, Puma,...) but I wouldn't think that a well-rounded sensor package with hunter-killer capabilities is needed. More something like what the PzH2000 fields for direct fire engagements.
An independent commanders sight with TI and a LRF and not something like the FCS of an IFV or MBT.
I am also not sure if HEAT round is needed.
Everything up to an IFV should be really impressed by a normal HE and a modern MBT is not impressed by a HEAT.
Mortar rounds pack almost as much HE as a 155m and are rather compact, allowing for a lot of ammunition. They are unable to come anywhere near the pentration power of a modern artillery and tank rounds but then again that's what you have the heavy tanks and artillery for. And in low-intensity operations low penetration power of the mortars (perhaps in with a DIME round) may even be often an advantage.
The AMOS is certainly able to rain down an amazing number of rounds in a very short time (26 in a minute, 8-10 simultaniously on target - MRSI) but it is IMHO a bit topheavy for light/medium AFV. A Boxer, CV90 or a Puma would be great platforms for it. The lighter AFV should use a turret with a single tube.
The trailed 120mm mortar retains anyway its great importance...
6 Hours Ago 02:18 PM
My comment about MBTs and IFVs also fullfilling the role as a HE thrower aimed more at them being much more often close to where the direct fire support is needed.
Such a mortar system could defenitely be usefull when used as a direct fire support platform but most of the time one is going to use the MBT or IFV which is close by or a (guided) mortar or artillery strike instead of getting a mortar unit up front which also might have much better things to do than act as a direct fire support platform.
I would go for the two barrel/IFV chassis combination as support for mechanized formations. These units already field the IFV, making logistics easy. And the heavy chassis would be able to support the AMOS system while giving good protection.
When doing it one can do it right from the beginning and get the best out of the system.
For light units I would not use such a system at all.
The planned Wiesel II mortar carrier for example is better suited to support light/airborn/airmobile/mountain infantry as it can go were a bigger mortar system cannot go while having a smaller logistical footprint.
And these units rely much more on being able to also use the mortars in a dismounted role.