Yes, it does seem strange that Ace went with no map. Nearly all fantasy books have 'em. They may be incomplete, and sometimes contradictory, but overall it really does help.

But it is also fun that there are so few GOOD maps in DoL. Mildmay is always grousing about it. I think the only accurate map Mildmay ever had was of the Mirador when he asks the head servant (?) for one. Because the servants HAVE to know.