Deep16,
To do that you would first of all have to agree on which set of the various harmony rules are actually "best practice", which may in itself be more difficult than you think.
You are also then faced with one bit of the RN/RAF/Army working to different rules to the rest of the RN/RAF/Army - and if those "different" rules are more restrictive/punitive they are a cause of discontentment, reason for experienced people to drift away from the role, discourage recruitment into the role, etc.....
Anyway, a point I made earlier, but which seems to have been ignored by everyone, is that many individuals (as opposed to formed units) in the RAF have regularly breached the current RAF harmony rules, but the system has either not picked up the fact, or simply ignored it, I'm not sure which!! The RAF rules may apparently be the most generous of all 3, but if they're regularly ignored then the rules themselves are of no consequence!