For me it depends on the job. I personally own and use most of what's on my list save for the 24" iMac and 13" Macbook Pro that my wife uses.
Some of the hardware is used when I am on location and need a few assistant editors, sometimes it's me using multiple machines to handle multiple tasks on location.
Somewhat similar situation in a studio or back at the home office. An assistant will be using one machine, while I use the others, or I have different machines handling different tasks at the same time.
For me, getting multiple machines to do many medium weight tasks was a bit more cost effective than getting on $7000 workstation to do them all at once, and at times, I needed the machines to come with me, so multiple laptops it was.
Ok, I get it know 🙂 thanks for clarifying.