BOAC hit the nail RIGHT ON THE HEAD.
Studi says:
I really fail to see how 1500 hours in a navajo would give valuable input to the captain here.
I might suggest that the reason you don't see the above, is because you have never done that.
I believe that it is much more important to have good knowledge of the aircraft you currently fly (thanks to a good typerating) and of the surrounding operation of your company (thanks to a good linetraining).
That is a given, for ANY level of experience, in ANY flight operation.
There may be 'cultural' considerations as well. In Australia, the percentage of 'low time cadet type pilots' who fly RHS is a small percentage of the overall 'multi-crew-jet-airliner-pilot' group. Even then, their total time is also made up of a few years of either being seconded to regional airliners (a recent re-introduction; years ago they were seconded out to GA flying for a couple of years to gain experience before returning to 'mainline' flying) and then a couple of years as a 'Second Officer' before progressing to the RHS of a 'multi-crew jet airliner'.
In this country, the 250hr co-pilot is a very scarce, dare i say', non-existant situation. It is a rarity in the USA as well, I believe.
Another thing I might add, is the mantra that 'single pilot operators' are hard to convert to 'multi-crew flying'. This is a load of rubbish. It's another skillset, and CAN BE LEARNT (for 99% of pilots). If you were smart when you were flying single pilot, you were using some multi-crew techniques, except you were doing it ALONE. You would use CRM, except it did not mean
CrewResource management, it meant COLLECTIVE Resource Management.
Again, you don't understand these values unless you have experienced it yourself.