Questions, questions...
They tried AEOs and AEOps for Tornado in the 80s and they didn't crack it - hence the big uptake of Navs for Tornado in the late 80s and early 90s to replace the aging F4/Bucc/V-force Navs.
Stealing since 1942 eh? Try 1915 when the Observer was first used in WW1 - this turned into Nav and Bomb Aimer in 1942. Air Gunners started 1939, which broke off into Air Signaller in 1943 and Radar Observer in 1941 - blobbing them up into AEO and AEOp that did not come along until 1963! The biggest travesty was when the WSO and WSOp was formed in 2003 by blobbing all the aircrew brevets into 1 - apart from the FCs, ATs, IAs and PJis!!! The original plan was for a 2-wing badge for FJ Navs that would be renamed Weapons Systems Officers or WSOs like the rest of the Western World. Somehow, some bunch of senior officers f@cked it all up and came up with the abomination of the WSO/WSOp and the d0gsh!t badge that goes with it - they would have been better bringing back the Flying-O Observer badge as it at least it had some history behind it (in fact it would be more senior than the RAF pilots' wings as they came along in 1918 and the seniors would never have supported that!).
As for RW WSOp LL nav - funny I thought the co-pilot did that and the WSOp dished out the Mars bars and manned up the General or the Mini-Gun on ops?
Don't forget that Navs have been using RWR/RADAR in Meteors/Javelins/Buccs/F4s for as long as AEO/AEOps have been around since 1963.
Finally, if you re-read my post you will see that I said you can train anyone to do anything (mostly) - hence that is why the AEOps that you mention became Tornado Pilots and Navs.
LJ