I have not read the entirety of this thread but my own view is as follows.
The people who like me tended to have an EHCP that had any value ( has funding attached to the kid) had children so severe that the private school they were at made an excuse to get shot of them end year 2. No private school keeps kids like that as it might dent their results. The only private school available to them is a specialist school and these usually are in the middle of nowhere.
An EHCP is not a panacea.
An EHCP is meaningless unless there are the funds to provide any 1:1 etc - this is called ‘high needs / low incident’ for a reason. To get this type of funding your reports are will refer to percentiles eg 4 or below even as low as 0.5% etc. Your reports might also refer to complex needs.
To get this level of support it won’t just be an EHCP report - there will be SALT, OT , audiology, sensory services etc. The cost of tribunal is huge.
The tribunal is pro local authority, the Ombudsman is pro local authority, the NHS reports are constrained by available resources.
Any services written into an EHCP can be reviewed and written out the year following - it’s an ongoing battle.
School can even say we can’t fit another LSA into the classroom etc
Anyhow even being a legally trained professional I have never experienced such a thing as an educational tribunal - it’s the Wild West of law.
So good luck if you think that you can take on the local authority and the system because I found it exhausting and distressing. It will eat into all your free time and cause distress. What’s more it’s reviewed yearly and whatever provision is in it can be removed.
My son finally managed to get some A Levels and a university place but it was one long fight.