And one of my examples was that consistency would allow easier moving from one set to another, i.e. improving flexibility! The trouble when you have different teachers doing their own thing is that the kids are effectively "trapped" in the set/stream. That was one of the highlighted problems with the 11+ and the sec mod/grammar system, yet still happens today - the so-called flexibility of the comp system is often just an illusion due to inflexibility, in part caused by lack of consistency/standardisation.
I'd love to see a system where no only is it easy to move between sets, but also to move between years, i.e. to accelerate or slow down your passage through school rather than the rigidity of everything being dictated by date of birth.
I'd also scrap the exam system and current subjects too and move to a modular system where you accumulate points from numerous successfully completed modules to count towards your eventual grade. I'd have modules particularly for various skills, such as logical thinking, cause & effect, etc rather than using a subject like history to teach cause and effect.
Finally, I'd encourage teachers to have a few years of experience outside schools before returning to the classroom. If that means higher pay to attract people with more life experience, then I'm all for it. Far too many teachers just don't know a life outside school - they don't know what a modern day workplace is like outside school. From what my son says, and his grades and from our very brief meetings with his teachers, the ones who've come into teaching late in life, after having a career/work in other sectors have a completely different attitude and are generally more popular. And yes, I say, again, if that means higher pay to get better teachers, bring it on.