IIRC - Doctors become consultants when their overall skill reaches a certain level. This skill is increased during any training activity in a classroom. The change to a consultant is otherwise unrelated to their training in additional qualifications (i.e. surgeon, researcher or psychiatrist). If they become a consultant part-way through training one of these skills, they will be forever stuck at the level of training they had when they became a consultant. :(
When a consultant is used for training additional skills, they will only train other doctors in the areas in which they are fully qualified. So your consultant with 81% surgeon training will not be able to teach surgery to another doctor.
Therefore it is best to only train doctors as surgeons / researchers / psychiatrists who have a relatively low skill, so that they can gain their qualifications before they become consultants. Once they have gained their qualifications you can use any consultant to raise their overall skill to the level where they become a consultant themselves, so that they can train others.