Sirsoky - no, the RAF don't have a monopoly on good ideas but cheap ones seem the preserve of the civilian market where grand promises are frequently made to provide equal quality but cheaper and where failures to achieve same are plentiful.
Are your paramedic converts going to Valley for their helicopter training by any chance? Using the SARTU syllabus or similar and run by ex-mil rearcrew?
The only thing your method is achieving is to depress rearcrew salaries because a paramedic who was used to £25K is much more likely to work for £30K than a qualified winchman who is used to earning £40K.
Most SAR rearcrew are dual qualified so they can be either winchmen or winch ops, primarily for difficult wet jobs where a winchman could get exhausted or to cope if the winchman is injured. You can get your paramedics to keep the wire straight with a relatively small amount of training but, compared to a dual qualified rearcrew they bring little to the party and reduce the overall effectiveness of your expensive SAR helicopter.
Cheaper isn't better and at some point it will come back and bite you on the ar*e. Why wait until an accident to realise short-cutting training is folly and a false economy - it is obvious to all those who have a real understanding of SAR. Don't look at the easier and straightforward jobs to set your operating standards, use the really nasty ones that have only had successful outcomes because of the high quaility of the rearcrew - that comes down to experience and really good training and they cost money!