What do you mean? The examples show use cases we have to think of. When designing worlds, or at least rooms players walk in freely, these questions about doors must be answered.
Ideally, of course, we could just physically model them, and then: wooden doors can be hacked away with an axe, a steel door could perhaps be forced using a crowbar but not if the frame is reinforced, etc. But, the modelling based on actual physical behavior is hard, both coding wise as well as computationally wise. So, we accept that we must do a simplified model and yet we must make it not too simple so that it still believably acts as a door in the virtual world.
I mean surely you don't require that many "specialists" to address all those concerns. It's like saying I need a chef to salads, another to make condiments, one to work the grill, etc.
It's just a list of roles. On a one-man project they will all be done by the same person. But obviously as budget scales up you can also split up the roles more and more.
Ah, so you were referring to the second section? I considered that as a bit of a tounge in cheek, but frequently AAA titles would create tasks for most of these positions. In indie development, sure some or all of these roles would be combined into a single or several persons. That does not mean that all (most) of these would not be done, though.
