D. Not really. I look at the total result when two assemblies, A and C, of mass elements collide. A is connected to ground. C is free to move/drop.
E. Yes, the ground is a very important factor to consider. A third assembly of material points.
F. Yes, A will deform relative ground, as will C, at contact C/A. The question which of A and C will fail first is subject topic + whether C can one-way crush A to ground.
G. See F. Has gravity a tendency to squash both assemblies of material elements, C and A, in collision? Deform, yes! Squash, no! Anyway, when a failure occurs, in C or A, we are no longer talking about C and A any longer. It is Cfailed and Afailed that must be considered in what happens then. Quite interesting matter. Some people suggest a new assembly of elements pop up! B - an assembly of rubble, apparently of failed elements of C and/or A.
H. I like generalized reasoning. So far nobody as been able to produce an assembly of mass elements A+C, then taken off the top piece C of this assembly A+C (C = 1/10A) and dropping C on A to produce a one-way crush of A. It seems it is not possible. I have made an axiom about it. Please demonstrate that the axiom is faulty.