Usyd used to publish its atar acceptance range and median atar but I couldn't find it again on the website. However I took a screenshot when it was up if you want to use it for reference
https://puu.sh/xn7yi/f190cc5077.png
Even with EAS the median atar accepted was 98.85. I've heard that usyds broadway scheme allocates spots aside where EAS applicants are placed in a different pool, with the most competitive ATARs being chosen first to filled the spots placed aside for them. But I'm not too sure about the workings of the broadway scheme so take this with a grain of salt.
If you don't make it into usyd law and you're set on it you always have the option of transferring in later. Good luck though !!