Everybody is starting to fuse Bleach with this Sasuke-Orochimaru fusion. I believe that Orochimaru is still not dead, and just in Sasuke's mind. Sasuke can be just holding off Orochimaru temporarily, yet does not have the ability to use Orochimaru's jutsus unless he learned it from him during the 3 year jump.

And also, I highly doubt that Sasuke need to change into Itachi's body. Sasuke wants revenge on Itachi for killing his family, not the ability to obtain his body like Orochimaru. Sooner or later, Sasuke's Sharingan eyes might evolve differently than Itachi's and Kakashi's, so that's what I'm anticipating about right now in the manga.

As for Sasuke's "brigade", I'd probably say that he's fighting Itachi head-on. At least, I hope.