I would have to look at the spoilers/leaks again, but I thought I read that a disguised Sauron would not appear in season one, or not until the end, so I think all of season one will be fore Numenor is destroyed, or even corrupted, by Sauron. Maybe season one is the introduction to Numenor and the main characters, season two is the corruption, season two ends with, or season three starts with, the destruction, and the rest of season three, and future seasons, are about the founding of their kingdoms on the mainland?