No special rules for this one and five victory banners to win, so it's likely to be a short game. With only four Command cards for each player, we're both going to have few options each turn.

Evert gets the French first this time, but the Prussians move first. I immediately moved the Prussian cavalry forward on the right to help block any French advance through the marshes. After using the Horse artillery to soften up the French Light infantry on the left end of their positions, I sent in the Prussian Heavy cavalry. And then pulled them back when the infantry retaliated so I could use the Horse artillery on the unit left in square.

Skirmishing continued centre-left until Evert played a "Force March" to move the French infantry forward in the centre. I used "Counter-attack" to move up the Prussians and both sides exchanged musket fire. A "Counter-attack" from Evert saw the French Line take out a Prussian Light to start the scoring: 0:1.

The Prussian Lights retaliated, so that's 1:1. The battered French Line fought back to remove another Prussian Light: 1:2. And the Prussian Horse artillery finished off a French Line (with a "Bombard" card): 2:2. A final French attack in the centre saw infantry into the village and the score 2:3.

The French right-flank cavalry finally moved, half advancing into the marshes, the others moving into the centre. A "Cavalry Charge" saw the Prussian cavalry attack on both flanks, the left flank Heavies under General Schmude chasing the French artillery towards the back of the battleground. The other side's "Cavalry Charge" saw French cavalry attacking into the centre. It then pulled back to finish off the Prussian Heavies, Gen Schmude making his escape through the French horsemen (we had to look up the rules for this - it doesn't happen often). That's 2:4.

Gen Schmude joined the Prussian Horse artillery as it finished off battered French Line to make it 3:4. However, the French cavalry finally completed the job in the marshes on the right: 3:5.

Despite (because of?) the restrictions, this was a more normal game, taking nearly 90 minutes for 26 turns. And a fine win for Evert.

I’ve also posted this report on my BGG blog (with pictures!): boardgamegeek.com/blogpost/188431

Vittoria Francese 5-0. I prussiani avanzano con i leggeri e l'artiglieria a cavallo sulla loro destra costringendo la fanteria leggera francese a ritirarsi nel bosco con gravi perdite. La fanteria francese muove timidamente nel centro in attesa di ordini per assaltare Nossentin. I dragoni di Schmude si fanno strada e caricano un'unità francese che resiste in quadrato. Bernadotte sposta due unità di cavalleggeri nel centro e manda Tilly a occuparsi degli ussari prussiani. Con un ordine di Marcia Forzata tutti i leggeri prussiani escono dalla città e assaltano le posizioni francesi. La linea francese regge però l'urto. La battaglia termina quando muore il gen. Schmude costringendo i dragoni prussiani a ritirarsi e per la carica della cavalleria di Tilly che attraverso le paludi elimina gli ussar prussiani di Pletz.

The French combined their artillery in the center and began bombarding while the cavalry moved around the Prussian left. A Prussian cavalry attack on the French artillery was unsuccessful. Eventually the Prussian infantry attempted a desperate bayonet charge of the artillery line, breaking through but decimated by a counterattack by Drouet. F5-P3.

In the Waren-Nossentin scenarios, the river tiles are actually represent the start (shoreline) of the lakes. The hexes (open hexes) behind the river tiles are still part of the lake and are also considered impassable terrain.

Answer is here and as i said, all hexes are impassable

I assume impassable too, because the river tiles and the tiles within represents the complete Lake Fleesen.
But i fear, the scenario designers didn´t remember the "Short Supply" card, it´s indeed important and should be clarified better in the notes.
I´ll check it

Are the river tiles and the tiles within them impassable or just the tiles within the river tiles?