Infrastructure workers contrasted with knowledge workers - interesting paradigm. I would agree that it has some validity, but I am curious into which group you would plug field scientists - biologists, paleontologists, archaeologists, and the like. There are surely other occupations that muddy the distinction.

My take is that there is often significant blurring of the two hypothesized groups. I have certainly met many "infrastructure workers" with very significant abstract reasoning abilities.

I would say, that as far as tool display in an office setting goes, approach the issue cautiously and understand the practices within that particular group. In the office groups in which I have worked, a Leatherman tool is seen as a useful item. Nothing works like the pliers at clearing paper jams in the printer or copier. I have been surprised at how often carrying basic first aid items on one's person has been really helpful in an office setting.