'If a child is classed as low functioning though, would they not (in theory) have to provide more input and resources'
Possibly. That's why I say go with whatever 'label' gets you the provision. You'll know in your heart and through your research what the real situation is.
But always remember, it isn't about provision, it is about outcomes. You can 2:1 TA support and 10 hours a week in a sensory room but for what? Expensive, lovely, but what is your child learning?
My favourite saying at the moment is 'outcomes not hours'. I couldn't care less if my ds' TA was working with another child when she should be working with ds PROVIDED he was acheiving.
And you're right. I get pittying looks when I suggest ds can learn faster than he is. I was told a couple of weeks ago by the Autism Advisory Teacher (the one that I got to replace the first stupid one) that 'his autism isn't going to go away you know' (quite possibly even stupider).
The H/L thing is only as relevant as it is relevant to YOUR DD/DS accessing help. There are very LF adults out there writing books, giving talks etc, but can't dress themselves and aren't able to use the toilet independently.
I think THE MOST IMPORTANT thing to realise is that if YOU don't believe in your child, your child is fucked. Sorry, that's quite harsh but who else will? What a burden eh?