Thanks for comments , advice and analysis ! It shows a vast array of options...
Yes, my 6th Army has been put in an incredible mess in the south of the swamp. I already started to pull it back but it's painful. In the north of the marsh the situation is not brilliant neither. Just hope the 2nd army received in reinforcement will be able to help getting out this marshy mess.
Picture below shows the development of the situation (played before reading your various comments). But now I'm afraid they take Lublin !

(( Will send 2nd army south to protect it. I'm obliged to retreat. It's a disaster
This game is incredibly subtle and the level of strategy is impressive. I'm really struggling as a German against the AI and so far I haven't had a chance to succeed.
But I'm having real fun !
