You generally want more air being pushed in than what's being sucked out. That will ensure dust is being sucked through dust filters, and that any open holes (ie top) have air flowing out of them so that dust doesn't enter there.
Each fan on an AIO counts as 50% of it's rated CFM (at best) since there's so much resistance. Yes, even if the fan is high static pressure (which it should be). Push+Pull on an AIO doesn't = 100% airflow.
For your situation, I'd put 2x140mm fans in the front. The AIO in the rear. And a 120mm exhaust in the top.
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