IMO it would be wrong to adopt any "absolutes" in aviation. And as far as I'm concerned the drive to adopt much of the FW procedures into RW flying is too much as it is. It's just not quite the same type of flying. But you have to know what you're doing. Probably a reason why NASA managed to train monkeys to fly FW but not helicopters yet..
The PIC needs to ensure he/she does not get overloaded. It may mean to take on the PM role and let the SIC get on with it, or take on the PF role if that means an acceptable workload.
As far as training is concerned I advocate understanding and knowledge of aircraft systems as well as environment. Doing anything by rote will become a liability on that one day that you should have stayed in bed.
To ensure that one needs currency in both roles. And never underestimate the learning effect of a good debrief, for both PIC and SIC.