I've trained a fair few ex army, RAF and Navy ranks in the past, as well as a few ex foreign forces. Not trained any ex para reg lads but I know a few bootnecks who were para reg beforehand. Most para-marine or marine-para transfers I have come across have transferred for location reasons. There's no bootneck units in the south east, likewise there are no para units in the SW or scotland. People don't join to be close to home but when marriages, kids or family illnesses are thrown into the mix things change.