"The offline program is not marcomage...its a version of arcomage."
Well yeah, I said "You can get the normal Arcomage here". So by normal Acromage I meant normal Acromage :D
To allow playing against yourself looks really awkward to me. If we really want to make "single player" in MArcomage, I would be in favour of developing some AI. It doesn't need to be very smart and also could be set to some behaviour (aggressive, defensive...). It would be probably used mostly for deck testing anyway. You could even provide a deck for the AI or it would just play with some pre-defined deck.