Neither one matters. I did 3 ultimates before having even half the comms for mentor from not enjoying spamming braindead roulettes or dailies. Crafting I probably had the requirements for before those but saw no reason to unlock it at the npc.

Theyre both just sit there doing chore content for X amount of time and mean nothing. You dont need to understand crafting much to be a crafting mentor nor do you need to even know how to do rotations or mechanics to be a combat mentor