I'm not quite sure what you mean. I don't see how the order is important here (low ranking school means easy exams + poorer mentality vs. the opposite way around) since they are still linked together. Can you clarify for me?
You are making the claim A = B, and therefore concluding A = B. That's not a proof.
It is not because you go to a low ranking school that assessments are easier and mentality is poorer. Rankings of one year do not affect the following year's cohort. Again, rankings are unofficial, and not completely accurate. A school could have every single student achieving a 98 ATAR yet be ranked last in the state. Simply, every student achieved a score of 89 in high scaling subjects. Those unofficial rankings are determined by the number of Band 6's, so despite a median ATAR of 98, that school is still ranked last.
You can say 'schools that have easier assessments and poorer mentality tend to be lower ranked', but that's the extent of which you can make such a claim.
Since they are still liked together, is it wrong to say that going to a low ranking school means: 1) it will be harder to differentiate from poorer performing students due to easy exams + marking and thus you will be dragged down (assuming not 1st) and 2) you will be in an environment which does not really care much about studying which will impair your motivation? Hence, school ranking does have an impact on your ATAR (not directly but indirectly from the points above).
Again, you make a circular reasoning in an attempt to prove your point. You start off with what you want to prove, i.e. 'easier assessments and poorer mentality is linked to low rankings', then you make 2 points, which you then conclude that 'school rankings affect your ATAR' (which is the same as what you were attempting to prove). That's not a proof. It's like being asked to prove 'sin
2x + cos
2x = 1', then you respond with 'well since we know that sin
2x + cos
2x = 1, therefore, sin
2x + cos
2x = 1'.
I'm not saying your points are invalid - your points are most certainly valid, but they are not attributed to simply being in a low ranked school.