Query: A base is contacted in the flank and rear by two separate enemy TuGs. By turning to the flank with an M2 move, the base would lose contact with the other enemy UG. What happens?
Answer: The base can turn to flank, but the enemy file that would lose contact can be shifted to remain in the contact with the base.
Let me get a step further : the enemy file may be shifted but the whole TUG or just the file ?
There are cases where moving a whole TUG could be impossible so I ask the question before it happens
I think "the enemy file" is pretty clear that it is file not UG.
As the question is framed that the M2 move means breaking contact with the enemy contacting the rear (as it is making a turn to the flank) I do not see that just specifying file will cause problems - but if somebody can illustrate where it might I'm sure we can look at whether further clarification is needed.