Issuing Orders

I don't currently have unit formations written into my game rules.  It seems that almost every Napoleonic themed game has some level of unit formation.  Are there any sources which describe what level of detailed commands were issued at what level? 


In my v1.0 rules, players command roughly division sized forces.  From the reading I've done, it seemed that battalions were the basic operating units.  It would then seem (from my experience) that for the most part, the battalion commander would receive orders such as go there, assault that, or hold this.  He would then reissue the command with additional detail such as formation, speed of movement, and/or precise route and timing.  Is this understanding historically accurate?  I know there's no such thing as absolutes, and every military regulation has a waiver or exception, but in general, what orders did the division commander issue?  Which issues were issued at lower levels? 


In the wargames where players can/do control division or larger size forces, are players playing the role of multiple people?  Do they know/understand that?  How does it affect play?  Please feel free to respond to any/all questions in the comments.