help from free benefits advice centres

I or my partner have no experience of any welfare claim. Now my partner had a PIP claim form to fill but can not read much because of a Trigeminal nerve pain triggered in an eye if try to concentrate / read , so requested a local advice centre for help fill the form.
But I wonder the advisor would give only 3 names ie GP and a Neurologist and a Cardiologist , saying there are only 3 places in the form. Advisor did not add 2 more specialists ie Opthalmologists l and physiotherapist at local hospitals . I was not allowed to make any suggestions eg a paper can be attached to give more info. I have to ask would it go against claimant if any thing is added in a different handwriting after original form is already filled in advisor's handwriting but eg advisor did not add a medically advised excercises regime I have to encourage and supervise for management of cardiovascular conditions .
And what about a wide belt always needed to fasten to support the back bone before walk /excercise , it is not an aid? - yes belt is covered dont want it to be visible to others.
And yes can not bring any proof other than partner confirming that claimant can not manage money but if claimant dont say they cannot manage money , it would be wrong , whether we can prove it for PIP or not, a fact is a fact.

Don't worry about there being only 3 names of medics on thje form, DWP rarely contact them anyway! It is better for the claimant to submit any supporting documents, if they have them, rather than hoping that someone will contact the medics.

Thank you . You made it so clear, it is the claimant's details whosoever completes it correctly with claimant's consent, DWP would need independent evidence for everything anyway. Some of the missing information was added but not the belt they wear because of a left side bend in their back bone. The form sent SD to meet deadline , the claimant found it all too distressing they would not call DWP to request an extension. No explaination offered for different handwriting . I have added a statement that besides other help, I do all the reading /writing of documents becuase the claimant's Left eye neurolgia does not allow them do it. But I did not say anything about money perhaps need independant evidence from a specialist as to why the claimant finds even basic numeracy so difficult to cope with.But the problem is claimant hates any sychiatrist / psychologist appointment - already fed up after suffering for so long from so many painful physical disorders .
It is my fault I have just started going through the B&W PIP guide. Though I hope it would be a big help to understand / negotiate claim process as it proceeds.