It is an interesting question. I have thought about it a bit too. In theory, the special counsel is more independent and can just go and bust down someone's door if that is how he is feeling the case should be handled and can go anywhere and look at anything because he has a full witch-hunting license, whereas Huber and Horowitz have to stay within their lanes.
That's in theory. In practice though, the special counsel we have now- Mueller- is only interested in using his powers against Camp Trump. So while Horowitz and Huber theoretically have less power than an independent counsel, they are in fact using whatever powers they have to in fact look at FBI misconduct.
As you said, it is winning even if not ideal. And it is possible that if the IG report is too ugly, then Huber will just be converted into a special counsel. And Rosenswamp who is one of the main criminals- would not necessarily be the one to write the special counsel appointment documents if there are charges related to clinton investigation misconduct. Sessions is not recused on that. He is mostly worthless but also looking for a chance to save his job so he might do it if he does not fall asleep while working on it.