TBH they shouldn't.
Employers don't really check your ATAR/UAI, it's your university results they look at more as it shows how well you can handle being independent. For instance just look @ how many people drop out of uni even though they got 90+ ATAR; yet many who got lower stick it out to the end of the course and actually attain a Bachelors. (this of course could be due to the numerical differences in comparison to averages but...)
However coming in the first of the state in anything will makes you look more unique.
Source: Family who's company in-house checks potential employees, and my family member is the interviewer.