According to a comment in the discussion of Argothian Elder:
How is that? In order for Argothian Elder to attack it has to tap, per rule 508.1f, and if Argothian Elder is tapped it can't be tapped again to activate the ability.
If you could attack and tap to active abilities simultaneously, it'd work, but I don't think you can.
So is the comment wrong or am I wrong?