Are you sure about that? You didnt have to provide medical records or go through the job centres medical staff before..did that change? It obviously helps if applications are backed up by doctors/professional reports/something other than your own word,but its money to help with care needs not to do with employment so its different to the incap/'employment support' allowances,I think..
I think the internal assessments are just for the ESA.. but when I checked online and with my advisor that was the information I was given. Although, it wouldn't surprise me if they misinformed me.. it wouldn't be the first, and certainly not the last time!