Yes, England vs Aus or India is the most important (particularly at home), but the other series shouldn’t be disregarded. I’m not sure NZ or anyone else would appreciate their series being classed as a warmup for another series. I think you still need to take these series seriously, regardless of who it is against, or whether it counts towards the world test championship. I am all for trying out new players, but there needs to be justification for doing so, and a core of established players in every match, treating it for what it exactly is... a test match.