Had this discussion with my Boss yesterday. It seems strange how the RN doesn't really "hate" our police - we treat them more as morale-boosting entertainment value. Also, our police transfer from other branches, you can't join as an RN Copper - which tends to get them called "source branch failures". Also, they live with us in the same messdecks, and work alongside us. Also, if we get caught, we tend to put our hands up and treat it as part of the game - after all, you normally get away with 90% of crime before making a silly mistake.
The Army seem to hate anything that resembles provost, as do the RAF - because they are (or believe they are) pro-coppers? We are not looking forward to tri-service policing as your guys' good/bad habits may rub off on ours.