Wait if your atar estimate is below 95 with those decent ranks, i don't think 99+ is possible
Obviously your school thinks the cohort of each of your subjects are shit and the fact that they are very small probably explains why your atar estimate isn't that high. I saw you post before that your cohort is really strong, if that's the case and they are very smart then I think 99+ would be possible given that you absolutely crush the externals, but i'm not so sure about this given your school ranking