no - where do you get hat from?
Or provoking? Heck you're already on a battlefield with "intent"!!
They can move to rearrange their troops as they see fit - within the limitations of being unreliable - which hopefully will be "properly" written some time soon.
It's not easy to rearrange troops when none of them can move closer to any enemy within 800p - for example rear ranks/reserves cannot move forward so most of it has to be done by retiring away from teh enemy.
Possibly with the intent, resulting from a behind-the scenes negotiations, or political calculations, of changing sides. If the enemy see you preparing to attack them they are likely to think the deal is off, or be somewhat doubtful when you say "We were on your side all along, honest."
Sorry, it wasn't clear from your original post whether or not you thought some restriction was needed, only that this one was pointless. Do you have something less pointless, but still limiting, to suggest?
I think an unrelaible allie should be able to to reform his defenses with retiring moves, the negotiations to change sides might not be going well and remember some allies are never going to change sides just not participate.
No matter if your relaible or not seeing your 'enemy' getting close to you or arround you would prompt any officer ( and more especially the troops ) to adopt a better defense. Leaving a line of Lh(F) to be charged by Lh(S) does not seem to make great tactical sense, the Lh(S) can charge you out of
Reliability making range for 1 pip, might make you reliable but might break your command striaght away.
OTOH it seems you are allowed to provoke your enemy because you can move towards him if your move ends 800 paces away from him, so it is ok to make threatening moves well away from your enemy.
Of course one could ask how are you provoking enemy by retiring away from him.
William