Well, covering the exits from that cauldron with artillery is nice, and will cause significant casualties, but it won’t prevent the entrapped Russian soldiers from escaping. They may lose a lot of vehicles, though.
—”but it won’t prevent the entrapped Russian soldiers from escaping.”
Sun Tzu said...
When you surround an army, leave an outlet free.
This does not mean that the enemy is to be allowed to escape. The object, as Tu Mu puts it, is “to make him believe that there is a road to safety, and thus prevent his fighting with the courage of despair.” Tu Mu adds pleasantly: “After that, you may crush him.”
https://suntzusaid.com/book/7/36/
As a major supply hub for the whole area, it is a serious loss. Particularly with Autumn and winter coming on.