It will be interesting to see the possibilities of the pairing, however, I wonder how a rifle with conventional layout would affect the shield-rifle pairing... since the bullpup would offer better balanceI agree. How often do we see anyone using a ballistic shield and a rifle? Pretty much never until now. Firing a rifle with one hand is basically useless if you want to hit anything. It is typically shield with pistol for that reason.
The fact that this allows shield and rifle pairing already shows that it probably is a massive reduction in arm stamina/strength requirement, transfering the load to the waist.
Now just pair this up with the leg braces and it could be a potential winner.