ACR is a take on the XM8 concept.Care to elaborate wrt the underlined part
ACR and SCAR are improved or simplified iterations of that modular carbine concept.
This is the image you posted to show the PLA modular carbine concept
Every variant illustrated matches to this XM8 display does it not?
Magpul Masada more than the ACR it would become more closley compares to the XM8 in modularity.
Only lacking in an Automatic rifle iteration.
SCAR does so to a lesser degree. It was designed with Special Operations forces in mind so a number of elements were removed as they were deemed unneeded.
HK416 is modular but is only as much as an M4A1 Carbine can be.
To expand this out.
XM8 was designed so that at an armorer level the entire weapon could be reconfigured to any variant of the family. An armorer could take the recever group and bolt of the XM8 And with a few tools build any variant of the weapon in half an hour or less.
This carried through to the ACR but at the User level.
Basically any user of the ACR could turn it from the basic carbine to a PDW in a few minutes with swaping of Barrel, Stock, and hand guard.
SCAR simplified this so that at unit armorer level again in a few minutes they could produce any of the basic variants, But for the more complex iterations like the Compact PDW, Mk20 sniper weapon or HAMR automatic weapon you have to basically get a new weapon because the level of changes to the recever, Stock and Gas system are more extensive. For tge US U.S. the divers of the SCAR were routed in lack of a modern 7.62x51mm rifle and issues with M4A1 issues that were the result of Early M4A1 being little changed from M4 Carbines save for the switch from a 3 round burst (M4) to full auto (M4A1). The issues at heart were corrected by changing of barrels and bolt modifications made by the US Army when it PIP and then switched to the M4A1.
Now HK416 is less modular by design and was only really meant to "Fix" perceived issues with the M4A1, and use with Shorter barrel Carbines 12.5 inches and below.
To reconfigure an HK416 requires a Gunsmith work shop and vice to build a new upper recever group to the requirements. Then that said upper can be dropped on to any M4A1 Or HK416. This level of modularity already existed with The AR15 family of weapons. The only changes made were that HK made the whole weapon Proprietary. So that other than the lower receiver group trigger pack and magazine no other parts are backward compatible. The only really modular part is the quick detach quad rail that can quick attack a M320 Grenade launcher.
So with XM8 an armorer with a work ship and the parts can take any recever and build any version you want.
With SCAR and a few tools you can build most of the basic models as long as it's the right model L or H. But the more complicated requires ordering from factory.
Masada at user level you can build any version you want as long as you have the parts. ACR simplified this modularity in line with ACR where in a unit Armorer would be needed. No LMG versions exist for ACR or Masada.
HK416 Or M4A1 you can build any version you want as long as you order the right assembled Upper recever group built at the factory or gunsmith level.
Based on what we see if the CS/LR17 And the table you produced labeled New AR4. It appears to me that we are seeing an XM8 level of program.