I think it is unlikely that many people without a military or law enforcement background will ever make any money in close protection (unless you have an in to that world like a family member who runs a company) the police and military guys have the best training and they got it free at the point of issue.
The reason the guys who have done the job for a government get the jobs is that they have a situational awareness that it is very hard to train into someone who doesn't have the right background or previous qualifications of being a soldier or patrol officer.
On the topic of medical qualifications there are loads of providers who run a course of a week or so and call you an EMT at the end of it, the NHS Technician qualification was a six week course followed by practice full time supervised by a training qualified paramedic. To become a Paramedic in the UK now you have to go to university they course is minimum 2 years most are 3 they are qualified to diploma or bachelors degree level much like nursing (the first courses were a copy with the extra street/ ambulance skills replacing some other bits of nursing).
Military medics do a minimum of 6 weeks to become a class 1 medic, the RAMC medics and the medics who work with SF or spearhead have stacks more time training and actual experience doing the job are various levels.