He obviously needs a buff and here are the reasons:
1. He has less Mastery than the other 3 GLs.
2. On top of the previous point, he can't manipulate Mastery, either on his allies or the opponent's team. (Jedi Lessons or legacy doesn't count because it's completely preventable and it's temporary).
3. As said previously, all the buffs JML gives to the squad are completely preventable, dispelable and when they do stick on the toons, their effects are meaningless.
4. His Ultimate does literally nothing, 100% Mastery? He's the only GL that has a limit on how much Mastery he and the squad can gain. The buffs that come with his Ult are, again, useless, they only last two turns and are dispelable.
5. He can be underdoged, beaten by old toons, does nothing special in Raids and just made a good Jedi team for LS GeoTB a little bit better.
6. He's only good paired with the so called "Titans".
IIRC CG said they're looking into him too (not only SEE), so I expect both of them to be buffed.