Moises, You will find a fairly comprehensive account of the Medical Staff of the regular Army in pps. 36 to 59 in the Bloody Fields of Waterloo ISBN 978-1-907417-41-2. Nomenclature and staffing varied with needs etc. As you realise, the AMD had little in the way of command and control of their units at this time, as can be seen from the Regulations for the British Army in the early 19th century. Basically, after the 'top tier' of DIHs, DIs, Inspectors, PMOs etc. the regimental hospital system lasted until 1873 and the regimental or battalion MOs were the 'GPs' for their units and the Staff Surgeons to the Forces were the more technically able surgeons, as has been said. The latter could be junior PMOs of an area, hospital staff, divisional or brigade surgeons. Many of the wartime staff appointments would work together (often with regimental colleagues) in hospitals or larger field hospitals during conflict. Junior regimental staff were used as frontline men, who could dress, control bleeding and arrange evacuation of casualties from the line. Physicians were elite, fewer in number and appointed to campaigns as needed. Many surgeons in the line and in hospital stations had to be physicians who could operate! Nosology, diagnostic skills and detailed understanding of disordered pathophysiology associated with trauma were little understood, but efforts by some physicians to organise hospital care and regulation, diet and attend to public health issues were sometimes exemplary (eg Dr Robert Jackson, Sir James McGrigor).