Aside from the fact that handgun rounds do not typically shatter a pelvis, that the largest part of the pelvis is the iliac blade and breaking off a chunk of it will not "break down the machine" (won't cause locomotor breakdown because the blade is not locomotor load bearing), and that few people have a clue as to where to shoot a clothed person in order to produce the necessary breakage/shattering to make locomotion not possible, shooting the pelvis is something of last ditch best wish shooting.
If you know where to shoot on a clothed person to actually break the pelvis and cause a structural collapse and are opting to shoot there because COM in unavailable, I would be willing to guess that you would be a good enough shot to shoot out the kneecaps.
With a rifle, it is a whole other matter, though hitting the iliac blade is still problematic.
Many people shot in the pelvic region go down - no doubt about it. Many people shot in the belly go down - no doubt about it. A goodly number of people shot in the leg with a non-bone involved shot go down. Some people go down when shot in the arm.
The PP presentation Bartholomew Roberts mentions shows at least a couple .40 slugs still in the pelvis region that managed to not break any bones. The pelvis was shattered, but by a .223 round.
Much to this effect, the "hip shot" is a way of breaking down the machine. Some crackhead coming at you isn't going to be coming very quickly with a bullet and some pulp sitting where his hip used to be.
Ah, now the hip word has been introduced. The "hip bone" is something of an unscientific descriptor used to describe the iliac blade or the lateral aspect of the proximal end of the femur. It is a term that may refer to the whole innominate as well, the innominate being comprised of 1/2 of the pelvis (ilium, ischium, and pubis).
So unless you are talking about RPGs for the whole innominate or .50 BMGs for the iliac blade or proximal lateral aspect of the femur, there won't be pulp where the "hip used to be" because bullets don't make all that bone disappear into oblivian and intimated.
Just like shooting COM doesn't mean the heart will always be hit, shooting the pelvic area doesn't always mean the pelvis will be hit and the pelvis is a whole lot larger, but if hit, it doesn't mean the structural integrity will be damaged in such a way to cause it to "shatter" or to "collapse," not with a handgun round.
Philosophy is nice, but biology and physics are a lot more relevant.