Agreed. Mako and Nowell shouldn't go for me - too big a risk. You need all your players available day one.
Alongside Slade who's not played a warm up and four players who had hardly played an international competitive game as well - if things go wrong for the team/squad - there are some potential pitfalls in terms of having players ready to take on a knock out QF (or indeed knockout pool game...)
I've been a critic of the squad selection - the injuries we know about (3) and players (57, McC, Ludlam, Singleton) with virtually no experience at international level plus those of limited experience (Joe C 7, Underhill, 8 and Francis 7 - including warm ups) and you've probably - in my convoluted maths, got a squad of rather less than 23 experienced internationals fit and ready to go
Of course - it could be a brilliant plan...but I'd feel a lot happier with some obvious squad omissions being on that plane!