tdracer
From what I saw over my 40 years as an FE there was a huge difference in operational methods between the European based and European influenced ( ie Qantas and BA) and the North American based and influenced cockpit ops.
There was no invisible wall on any of the 3 types I was on. It would have been a bit hard on the Boeing types as they were only fitted with one set of thrust levers. The FE was vey much part of the whole operations on the Boeings including checking radio read backs and nav waypoints. All checklists were run and read by the FE. From talking to other airline crews, most non US crews were the same.
Australia never got involved the ALPA type disputes and our unions overall worked well with then pilot unions. In the end the long haul pilots and FEs merged their unions and at least 2 FEs ended up as VP and Secretary of one merged union.
I can only speak from the long haul perspective, but I suspect that on this type of ops and being so far from home in the days of poor coms in many parts of the world, our system worked far better than the S/O s in the FE panel. I saw many a US carrier get themselves in trouble due to poor system knowledge and operational knowledge including one major US carrier who ended up with all the fuel in one tank on a Pacific crossing. Now that was an interesting inter aircraft discussion. At least they paid for our beers that night in Narita.