My two cents:
Best in the faction - Hamelin. Out-activation, Obey and Blight are so powerful... Quite easy to operate but booooring like hell...
Easy to learn: Levi, Viks, Misaki. Simple beaters which operate separately from the crew although Von Schill likes to have his Freikorps friends around to hand-over Oathkeeper to them and keep them alive a bit longer.
To be avoided for new players: Parker, Tara and Jack. Parker is weakest of them all. Tara with burying mechanics and Jack with Tormented techs might be difficult to use and i wouldn't recommend them to new players.