I do think that much of what has been written around these tests and young thrusters etc is all rather pee'ing in the wind. Whilst jones selected a rather odd shadow squad for the 6Ns, I wasn't sure there was much merit in those selections - when in reality - I think he's pretty sure of his preferred RWC team with perhaps the exception of 15....
If Marcus Smith etc get games vs Canada and the USA, what does it tell anyone? The key player that came through from the 2017 tour was Curry. But hardly a surprise - as he'd been through England age groups and then on return played for Sale, luckily missed out on 6N 2018, and then was on the SA tour in 2018.
West is already on the radar, played loads of games for us and is an experienced prop and ought to be at the RWC, Tom W is not really a bolter - U20 RWC and lots of U20 caps, and being phased into Prem rugby by us, good player amongst a plethora of England backrowers.
Josh - it's too late now - underrated, bujt his stand out characteristic of scoring tries, decent defence and leadership are unlikely to temp Jones...