It's sad to say, but the best way to play a higher up in the Witch Hunter division is not to be one.
Bear with me: In 'Into the Steam' the Infiltrator Profession has access to a ability called Infiltration, and this ability allows access to assets of a certain organization of your choice.
So, your status as a 'Witchling Handler' allows you to request a minion and an enforcer of your organization.
Say Hello to your new friends Witchling Stalker and Witchling Thrall. Splash some Overseer for your command tricks, a little sorcery skill for the fire tricks and finally a touch of heavy melee skill for those delicious greatsword tricks; and viola everything you ever wanted, with none of that pesky 'Loyalty' to worry about.
Funnily enough, if you wanted to go the Samuel Hopkins route just take some notice, track, and pistol skills (maybe some counterspelling for flavour). Pretty straight-forward guy, he is.
That's not to say that a little talk with your FM beforehand could save you all this trouble. The magic of this game happens when the two of you work together and make something (or someone) memorable.