You don't need Whithers to create a hireling with this mod. You can create one at any time with a staff the mod gives you. I've been using it for quite a while now, together with the "party limits begone" mod to create a party with a mix of races and classes I want. Both work on patch 7. The hirelings won't have much to say to Tav when he talks to them, but when they talk to other NPC's they get the lines associated to their class, and also participate in the "wilderness banter" sometimes.