Question:
Even if the rules are clarified to restrict the Germans to both moving and fighting only adjacent to Liege, no actual player will allow 3rd Belgian XX to escape the fortress as it historically did…if a player has no incentive to act historically and lots of incentive not to, the rule is probably wrong.

Answer:
True. An Entente player probably will not move the 3rd Div out. What a player might do with the 3rd Div may depend on other considerations. Note too that the the AUG I 14 Setup is not intended to carry over to AUG II14. MTV starts AUG II 14. Sorry if this is not clear. The “March to Victory” scenario is only the AUG I 14 turn. I added CP Setup MTV: to the AUG II 14 listing.

Source:
Mail by Eric Pierce to the Yahoo Europa Mailing List, 15.8.2016