If they were to go exclusively in the 4-3 Williams, Stroud, Troup, and Johnson would likely be the DTs. Edwards, Carrington, Kelsay, Maybin would be the DEs that are currently on the roster.
But I agree with this, he is not the defensive coordinator but a position coach/consultant and while his voice may be louder than the other position coaches in the room I dont think his signing changes any future plans for the defense.
I think Merriman and Moats man one spot while they bring in a high pick (top 3 rounds) to compete with or replace Kelsay.