Good point magenb on what my goal is for this topic. In multiple 40K books that I've read recently involving Dark Angels, Ultramarines, Cadian IG, and those books with the "best stories of..." from different writers.
In most of them an Inquisitor has a retinue of a 2-3 apprentices and/or bodyguards and a jocko(?), so I just wanted to just have some fun. In a couple of the "best of" books. There is an inquisitor that had a couple of battle sisters as bodyguards and I thought that was a good idea. Another had a squad of grey knight terminators as his own personal force to take a prisoner from one of the prison planets. I also know from reading 40K wiki, that Greyfax used to used Tempestus Scions as her personal bodyguards. I was changing it up to being two females with her, and using the grey knights as her personal attack force when taking down. From doing a little more research. Grey Knights are primarily used by the demonhunter inquisition forces.
But I will be looking up the Eisenhorn series. He was another Inquisitor I considered getting, but for some reason I like Greyfax a little more.