The 737 300 was FMC, not glass cockpit. The VNAV and LNAV was what we had never seen before. The FMC was the transition, not the glass cockpit which had not happened yet. I was saying it takes time to adapt to new technology. You don't do a two day course and sometime later go out and know what you are doing.
Yes, I know and I agree with you - certainly training as you described in not fit for purpose without gaining and maintaining regular currency. The -300 did of course have 2 years' additional development over the 757 that was already flying.
I often wonder how many operators retain that glass cockpit concept of standard round dials? Not many, I bet.
Same bizarre step option was available on the NG transition - you could have it delivered with 3/4/5 instrumentation portrayal on the screens or a full glass 777.
Degraded scan is a real problem at all levels of aviation, though I would go so far as to say that most PPL instructors don't place enough emphasis on it (if at all). Hardly helps when flying with an abnormal glass cockpit, and you don't even have a framework by which you regularly monitor the "right" outputs.