We've got students doing this paper too, but the Crime version. We've also been crystal-ball gazing and we are thinking it might be a case study of a particular place. Having been to one of Colin Sheppard's feedback meetings (which was excellent) he seemed to be quite keen on themes, and I get the impression the Middle Ages is his favourite so it could be something obscure for Medicine; the last Medieval Crime paper 2 we had was unexpected (Women, I think). There was an OCR paper 2 many years ago on the role of the church/monasteries in Medicine. I can root around for a copy if you don't have one and scan it for you tomorrow.
Sheppard also said that spending time covering the knowledge was not time well spent, and that it is better to go over source skills with them. We have prepped ours for paper 2 using past papers from three different time periods and, touch wood, this is the most confident I've ever felt. I've written a handful of exemplar answers for each question on a paper and asked them to put them in best-worst order, and pick out the best features of each one.
I have some more paper 2 tips from the feedback meeting if it would be helpful, but I think I've strayed from your original question now

just feeling evangelical about it because it seems to have worked so well this year. The proof will be in the results, though, of course.