There has been a House of Commons report recently.
www.parliament.uk/business/committees/committees-a-z/commons-select/education-committee/inquiries/parliament-2017/special-educational-needs-and-disability-inquiry-17-19/
In the Summary it says
"There is too much of a tension between the child’s needs and the provision available. The significant funding shortfall is a serious contributory factor to the failure on the part of all involved to deliver on the SEND reforms and meet children’s needs. Ultimately, however, unless we see a culture change, within schools and local authorities and the Government, any additional money will be wasted and make little difference to their lives."
As demonstrated by this thread, arguments that DC need to be incontinent and non-verbal (false) are deployed by schools to avoid applying themselves and to discourage parents from applying. Not for an EHCP but for assessment of need. Unfortunately it is simple - if you don't identify a need, you are not required to support it. There is a belief that the teacher's subjective assessment is more accurate than objective assessments carried out by professionals because teachers have to deliver provision. They therefore don't deliver provision even where an EHCP exists because they think (with no evidence) that alternative (cheaper) provision is more realistic.
DS2 had an EHCP specifying f/t LSA support but his school said they don't do 1:1 and gave him access to the class TA instead. Not all classes had TAs so he had to be streamed into classes for DC with below average attainment even though cognitive assessment by the LA EP put him in the 'gifted' 99th percentile. Not surprisingly classwork was not recorded (no 1:1 or use of IT), homework was not recorded, so not done, resulting in detention etc. DS1 became a gibbering wreck after a matter of weeks and was signed off by his GP after one term.
The SEN budget is not ring-fenced and schools allocate the budget without first identifying existing levels of need or considering needs of DC who join after the annual budget is agreed The budget is used to deliver a package and it is difficult to get bespoke support with DC with an EHCP who doesn't need nurture groups and cannot access the curriculum despite social skills group, Lego therapy etc.
This tension creates an adversarial stance with the child (and parent advocates) on one side and the school/LA on the other. One of the reasons why so many SENDIST appeals are successful is because assessment is inadequate and full assessments by EP, OT and SALT are only commissioned when Tribunal is approaching and the LA is desperately scrabbling around for evidence of the absence of need.
Listen to teachers but check the validity of what they say. Be wary of advice given by SENDIASS - they may prioritise local LA policy over the law. Visit the websites of IPSEA, SOS!SEN, NAS, special needs jungle and FB groups such as EHCP experiences.