As you can see from the following screenshot, Mailsmithing Deep Wilderness Gathering and Mass Blades and Hafts Crrafting are not consistent with the Artificing counterparts.
Here the numbers:
Mailsmithing
Deep Wilderness Gathering, rank 1: Reward 200 XP / Duration 7h
Mass Blades and Hafts Crrafting, rank 1: Reward 200 XP / Duration 7h
Deep Wilderness Gathering, rank 2: Reward 800 XP / Duration 8h
Mass Blades and Hafts Crrafting, rank 2: Reward 800 XP / Duration 8h
Artificing
Deep Wilderness Gathering, rank 1: Reward 200 XP / Duration 6h
Mass Blades and Hafts Crrafting, rank 1: Reward 200 XP / Duration 6h
Deep Wilderness Gathering, rank 2: Reward 800 XP / Duration 6h
Mass Blades and Hafts Crrafting, rank 2: Reward 800 XP / Duration 6h
tl;dr
Artificing is 25% faster leveling after lvl 15 (because yes, gathering is still more rewarding than anything else unless you don't go into rare tasks, which is a little unreliable).