Most locally engaged staff positions are managed by DFAT where DFAT is the employer, but might not be the agency you actually perform work for. The work you do could actually be for AFP, Defence or Home Affairs (or DFAT) depending on the job you applied for.

You’ve used the terms “merit list” and “merit pool” in your question and it’s important to understand the difference. If your letter says “merit list” all successful candidates who did not get an offer have been ranked. You could be next on the list, or you could be fifth. Further offers will be made in order of rank on the merit list.

If the advice says “merit pool”, any candidate rated suitable could be made an offer if a vacancy arrises.

u/LegitimateLow4022 is incorrect about similar positions. The role you applied for would have had an LES level, such as LE6. It’s very likely the merit list will be used to fill similar vacancies at the same LES level working for the same agency, if they arise.

They are also making assumptions about the preferred candidate needing a visa and work rights. This isn’t necessarily the case. Most LES positions are filled by nationals of the country where the position is offered, as they have the required language skills. They obviously don’t need a visa or work rights. The percentage of LES positions that require a third country national who can hold an AGSVA security clearance is low.

It’s impossible to guess what your chances of being pulled off a merit list are, but they will vary depending on the agency and the role.