As you say though, there is no way they can take away all the uniformed people from RAAF ATC due to deployment requirements etc. Although, some idiot in the Government may just try (hence the reason that at one point you couldn't find an army plumber anywhere in East Timor to fix a sewer).
Some sort of gentlemanly 'sharing' agreement would make sense though, as the RAAF really can't retain the ATC personnel it needs with the funding it has.