You totally missed the point of his post.
If object A impacts object B all of the mass of object A contributes to the momentum and therefore impact force of object A, regardless of how much of object A actually comes into direct contact with object B.
This is incredibly simple.
It is so simple that people like me, who come here to learn from people who know a great deal about physics and engineering, understand it completely. It is nothing less than staggering that someone who purports to be an engineer can display this degree of obtuseness.