I can take it, except one point.The most critical parameter are IMHO outer plate thickness (influencing the quantity of the "precession motion") and mostly the distance between plates that is neither enough to allow full de-capping nor the good one to ensure that the shell is hitting the inner plate with an unfavorable inclination due to the same "precession motion", while the cap is detached but still "rides" the shell.
In British report, there is something that “experiment using flash photography show that the armour cap is removed from A.P.C. B.C. shot by impact with thin mild steel or armour plate targets at all velocities above critical velocity”
than description how in various velocities cap could be removed, what would be variance of velocity and so on.
Than
The removal of an armour piercing cap by a thin front plate has an obvious application in the arrangement of divided armour, since, with the cap removed, she shot will be subject to shatter on a face hardened plate, the type of failure the A.P.C. B.C. shot is designed to avoid””
(bold is mine)
So we back to shell design.
APC BC was designed to avoid damage in condition with cap removed….
So no shatter in that situation, so no clear advantage of such configuration….