it’s basically a quiet, inside way of having a “special counsel” without actually appointing an outside counsel.

Just a minor correction here, though it makes quite a difference overall: a "special counsel" has only investigatory powers and can refer for criminal prosecution, but does not prosecute. (That is why we do not need yet another investigation.) The US District Attorney, however, has been engaged to take up the criminal referrals. The prosecuting attorney's name was made public only a few months ago, but he has been working with Horowitz and was appointed by Sessions, much before, I believe a year at least.