The devil is in the details, and it seems like there might be a pretty big one hidden here. Adventure board tasks show up with lowest rarity to the left, highest rarity to the right. Is this because they get sorted or because the slots don’t roll on the same tables?
I haven’t seen any duplicate tasks on the same day, so the tasks definitely don’t get rolled entirely independently. I wouldn’t be surprised if there are two “low quality” slots and one “high quality” slot, with only the latter one even able to roll up mythic, legendary and possibly epic tasks. We’ve seen this kind of handling before with the old iron keys and the legendary guild tasks system, it could further lower the average payout quite significantly.