Leeds played Castleford a few years back on the same weekend as England v Exiles and had 10 players missing. They played kids and actually won, 12-10 or something like that. They didn't ask for a postponements. They got on with it. Teams have an u20s and should use them.
Edit: it was 2008, Leeds won 18-12 and there were 14 players out.
Leeds have proper junior development some other clubs don't.
I'm pretty sure Doctor Koukash has started to put in junior development plans, but these things take time.
Some other clubs in Super League need to do a lot more on junior development.