This will be hard to implement. 5000 troops would at best represent a "small garrison" and the Germans are attacking with whole Army Corps.
It would require a French commander with a ridiculous defense value of about 15 to have a chance to avoid instant destruction from multiple attacks.
And I know my players: they would detach that commander and transfer him to Paris the next chance they get, n'est pas? Nice try, but not going to happen.

Besides there also were 50.000 Belgian troops involved in the Battle of the Yser.
So, what hex are we talking about here anyway?
In my opinion it should be the hex northeast of Calais at X:83Y:25, which by the way is blocked if the modified Schlieffen plan was chosen until the
Race to the Sea event triggers.
This is also swampy terrain which fits the flooding of the region background.
I would suggest to spawn either a French Reserve Corps if Belgium has already surrendered or else the "newly rallied remains" of the Belgian army which would amount to a half strength Belgian Army Corps.
If Antwerp has already fallen and the hex is still connected to Antwerp it would be a full strength Belgian Army Corps to represent the retreating Antwerp garrison that has joined them.
In any case the event will unblock the hex and trigger the "Race to the Sea" event in favor for Entente.
Should a CP unit capture the hex before the event is played, then playing the event will damage the CP unit on that hex.
The event will be available as soon as...well, quite early, haven't decided yet.
The event is discarded at the onset of winter in 1914 because of bad weather conditions.
P.S. "small garrisons" in Potzblitz are called "garrisons", which leaves room for misunderstanding. Maybe we should rename them to "Home Guard" or something like that?
P.P.S.
LepetitKipetchi wrote: ↑Thu Nov 19, 2020 9:49 am
The third option to destroy 3 Russian units looks too simple compared to the 2 other plans or we should destroy much much more units.
Surely there must have been a misunderstanding because I can't understand what you are referring to.