Engineers have schooling to design something. Where as Machinist have the schooling on how to make it.
Put a well trained and experienced Machinist in a machine shop and they will make what you want.
But put most engineers in that same shop, and well, just have the paramedics on hand. This is even more true with CNC equipment. I'm confident enough to walk up to most mills and go. Lathes, a little more time. But just see if there is any engineers that would have even the basics of what the control panel does?
As has been pointed out many times on this board, most engineers rarely have working knowledge of how a machine shop really does what it does.
And admittedly the same could be said of shop people of the puzzle offices.