Not being able to solve all the issues, I decided to bypass one: namely the "object" of the order (the target of an attack, the destination of a maneuver, and the like). Rather, the order gives the unit its general attitude (don't know if this is the correct word in english). Once cleared the path from this obstacle, I wrote several micro-sets of rules for each single Order type, namely what a Brigade MAY and MAY not do under this or that order. To further depict this attitude, also the movement allowance is different and formation is strictly regulated. I must add that Drums & Tricornes is an area wargame (the table has a square grid on it) to get rid of all troubles connected with linear movement and measurements (see my previous post).
I know it's easier to do this job for SYW (a mainly - if not exclusively - linear period), but I hope that if this solution works, maybe I can find some tweaks also for other periods.
So basically, instead of trying to write a rule encompassing all possible situation, I wrote more micro-rules in a format that can be printed in a single card (poker style). The format is something like:
MP: (Movement points)
Type of movement allowed: (forward, backwards, oblique and the like..)
Who can order it: (CinC or brigade Commander)
Formation allowed: (self explaining)
Change Formation: (allowed, not allowed, limited)
Change face: (cost in MP)
Combat Effects : (advantage, disadvantage)
Difficult Terrain: (cost in MP and/or Fatigue)
I did not (intentionally) limit - just to mention one - the number of attacks that a Brigade may perform (a Brigade is made of several Battalions). It is just the combination of MPs, formation allowed and what you may do that forces units to perform according to the order. To make an example: if you have a HOLD order and want to maneuver, you can do that, but very, very slowly.
If the situation becomes really critical (due to an order which is difficult - if not impossible - to fulfill) the Brigade Commander may invoke "Self-Defense" and break the rules (with consequences, of course).
I also added a simple method to send Orders almost secretly (your opponent knows that your CinC has sent out 2 orders but don't know to whom) and a brief sub-phase of order comprehension.
As I said in my previous post, this is not THE solution, but could be a reasonable start.
BTW, it seems to work (and to be fun).