Just because your from the navy doesnt mean you wont get work but royal may pip you to the job for HE work because they are recognised as being a more aggressive body with experience in dealing with hostility.
Adrenalins the same colour whichever service you once belonged. What alot of people forget is, what you were 10 years ago, becomes alot less relevant as what you were doing last week!!!!
There are plenty of ex Matelots, on the CP circuit and in Marsec. Just as there are plenty of ex Bootnecks, Perce and Crabs. As for companies preferring to employ one former service over another, I think that is ultimately down to the background of the guys that own/run the company. Its got nothing to do with RM being a more aggressive body, with experience in dealing with hostility. Within marsec the ability to tie a decent round turn and two half hitches would'nt go amiss, but some basic seamanship is often overlooked in favour of someone who can spin dits and looks good in a mirror.
We're all Mr's now and to be honest, if you've got a good cv and it lands on the desk of the recruiter at the right time you'll deploy. It also comes down to if you know someone in the company who can vouch for you!! There is plenty of work about, in CP and in Marsec for all walks of former serviceman. You just have to crack on and keep going, if you get knocked back, try again.
Having said that.
If you were a 12 year AB chef, trying to get into Marsec with a namet 9:9, colour blind and as overweight as the embarassment hauling down the ensign on the Ark Royal the other day, then I think I'd be thinking of working in a pie shop instead of marsec or cp!!!