This mission has a 100% success rate - even if the follower isn't level 100.
I was able to complete this with a level 91 Uncommon follower with no issue. Easy XP!
Most training missions (including this one) have a 100% chance of success and mission rewards, regardless of which followers you assign to them.
The person you send will not have their traits rerolled. They will come back with an item which you can reroll any of your followers you choose with.
I want to know if this is repeatable. I've only done it once on any toon.
I've been spamming missions nonstop since launch, 33 of my 38 followers have professions I want obliterated.
..Someday this will appear for me.
This mission needs to show up more, have yet to ever see it, on my main which has all followers at 100
Garrison Timer Mobile App
Missions and Followers math for maximising success chance
Warlords of Draenor Follower Guide
Warlords of Draenor Garrison Missions Guide