Don't pick on the retards
Andyy, that's like saying SH and AT are the same as it is transport, or a pistol and a sniper rifle do the same job just at different range (analogys are not my strong point!).
Some of the sensors may be similar but they are used in very different ways, that is the skill which needs to be maintained. Even the most direct comparison of Acoustic Operators needed to do full OCUs when they did RN/RAF exchange tour. It then took the same time as everyone else to become CR, the ones I know would be the first to admit that it was a steep learning curve to learn effectively a different role.