Rhys, if RAF Medic is undermanned and in the category of a 'Pinch Point' trade, then you should be asking yourself, the AFCO, and preferably serving RAF medics, why that is the case. There'll be a reason, and you should find out what that reason is before you commit to the trade.
Yes, they may well 'incentivise' you by giving you a Golden Hello, but the shine will quickly wear off if you end up thoroughly miserable with low morale, a few years down the road.
Always remember, employment is a two way process. You have to fit the job and the job has to fit you.
Good luck mate.