i like TTA, LoW and Agricola very much, but those are boardgames and not scratching a tactical turn based fantasy squad game itch.
ok, maybe Playdek's Summoner Wars.
btw the guest log in is no issue, as your custom ingame ID will be just linked to that. in the game you can create a wizard incl. equipment with your chosen name.
campaign progress is saved automatically, even inmidst the tactical battles.