Essentially, scaling is the process that allows UAC to compare relative student performance across different subjects for the purpose of ATAR calculation. A higher scaling subject means that the level of competition in the subject is high. Conversely, a lower-scaling subject reflects lower student academic capability. This is the reason that a subject such as Mathematics Standard is considered to scale lower than Mathematics Advanced. By extension, it can be assumed that a particular HSC mark in Mathematics Standard will make a lower contribution to a student's ATAR than an identical HSC mark in Mathematics Advanced. For example, achieving an HSC mark of 90 in Mathematics Advanced is likely to make a more significant contribution to a student's ATAR than an HSC mark of 90 in Mathematics Standard. In such a case, a slightly higher HSC mark in Mathematics Standard would be needed in Mathematics Advanced (e.g. 95) to match the contribution to a student's ATAR made by an HSC mark of 90 in Mathematics Advanced.
With that being said, a high ATAR can be achieved with any subject combination, as long as the most important element is satisfied. This element is your commitment to your subjects, which will allow you to perform at a sufficiently high level that would be consistent with a high ATAR.
Regarding English Standard, a 99.95 ATAR has already been achieved by a student who took this subject. This happened in 2022 and is a good indication that favourable performance is possible with any combination of subjects.
I hope this helps!