As with many other things in recruiting the answere to your question is - it depends.
If you are applying an occupation with local selection, with plenty of spots, then your placement on the merit list doesn't matter. If you are applying for an occupation with national selection, with few spots, and many applications, then your placement has a lot to do with whether you get a job offer or not.
If a person is applying for infantry, with over a 1,000 training vacancies in any one year, then the merit list placings doesn't really matter. Same with Naval Electronics Technician - although there are only about 100 training vacancies for all three occupations in a year, the education and CFAT score requirements are high, so if a person qualifies then they will likely be hired.
Now, if a person want to be a Pilot, with about 70 training vacancies in the past year, and about 500 active applications - you have to have something special even to be considered.