As someone mentioned earlier, Matt Limegrover was the OC/OL under Kill at NIU. There's definitely room for Davis to stay on staff even if Limegrover comes along.
I'm of two minds on Hammock. He is clearly a great recruiter and I think most of us would love for him to stay here (especially with his NIU connections), but he will probably be a candidate for their open HC job, or even an OC candidate there or elsewhere. Rob Reeves, Kill's NIU RB coach, has been with him a long time, so if he comes along, do you have a spot for Hammock?