OOC
Levi is an engineer, pure and simple, with medic as secondary role. He has some skill in a smattering of other areas but nothing to suggest he should take that as a primary role, such as Biology, Instruction and Admin.
Tanja is a true multi-role, Jack of all Trades so could fit in anywhere. Considering her primary role was a techie, she's now a decent pilot, astrogator, comma, sensors and engineer. Technical has taken a back step.