alice that's it, appropriate support is the key.
One reason inclusion doesn't always work is because the system for mainstream schools does not recognise that different teaching approaches are needed simultaneously. It's not enough for them to say "we're inclusive" simply because they allow a child with SN to attend. They need to damn well get teaching staff in working FT who have proper training in differentiated approaches.
At the moment it seems so widespread that children with SN are allowed to attend ms as long as their behaviour doesn't cause problems for teachers, and as long as they've got a babysitter who will just remove them from the class if they "kick off" - rather than training for teachers how to approach teaching in a different way, or to recognise triggers for behaviour that arise from other things like anxiety, social excusion from peers, difficulties interacting etc. It never fails to shock me that TAs can be just any old person from down the road. The most vulnerable children, with the highest needs, are given to the people with the least amount of relevant training.
Effective teaching for some children with some particular SN sometimes just means the CT thinking about what motivates each child to learn. Behavioural difficulties don't mean a child is unteachable in ms school, but that more probably, the child is playing up because the normal approach relies on a child having 'normal' motivations to learn (eg social compliance, not wanting to get in trouble etc) as well as being able to focus and understand (eg if a child has language disorder or sensory needs, having to sit still and try and understand a teacher just talking for 30 minutes is going to be really hard).
My ds has HF asd, and we also went through tribunal (also settled before) - not to get more hours on his statement, but to get a specific kind of support targeting social behaviour, play, and interaction. The LA had no reason to battle against us, as we weren't asking for more funding - it was more because what we wanted required getting staff in with experience in a spcific kind of approach which wasn't just the normal bog-standard TA with no expertise, using 'visual aids', and a babysitter to whisk ds out of the class if he was getting "distressed". The opposition was purely ideological, and had nothing to do with inclusion. What we have now really is a waste of LA money - a TA for 25 hours a week who has no need to support ds in the classroom, but only at social times - but without us and our own independent team who go in, there would be no training for her to do this. Crazy.
Sorry, essay over 