...I'm reminded of a quote from a grizzled old FE.
One of the less obvious benefits of the old 3 man Flt Deck was the fact that Pilots and Engineers (FEs) were trained differently which could produce a parallel and complementary approach to problem solving and priorities.
Given a telescope, a Pilot would naturally look
through it, an FE would look
at it.......
.......then make sure the Pilot was looking through the right end.