The 10th is at full strength, in reality it was rebuilding after horrendous (tank) losses in El Alamein (its armoured brigade was involved there, not sure about the infantry components) so the freeze is OK. Other units should not be unfrozen either as they represent a guard/protection force. They will unfreeze if enemey comes close.
If the enemy comes close to those units in that scenario then the player is in a lot of trouble.
I saw generals create imaginary "masses of manoeuvre" with a crayon and dispose of enemy concentrations, that were on the ground and on the map, with an eraser. Who was I to criticise them, hero as I was of a hundred "Chinagraph wars" of make-believe?