Sure, do that!
I mean, the General quite probably hasn't only one single underling!
And speaking of potential for "overlaps" (which I reckon were bound to happen sooner or later):
My next character will be a staff member.
And the character after that (or at least the little story I am telling in the author notes) might have the potential to interfere with the story you are currently spinning. If that turns out to be the case, let's just say that the events described in said author notes happen at a different time instead of in parallel to your story.
Author Notes: