I've played this scenario 6 times, and the French have won all 6 times.
Scores have been 15-5, 15-11, 15-11, 15-10, 15-6 and 15-10
The last playing included boosting all the Russian infantry up to 4 blocks.
boardgamegeek.com/blog/10429/blogpost/14...nfantry-modification
I'm thinking the problem lies in the awarding the French Victory Banners for the towns. 4 Victory Banners is often the difference here.
So I suggest as a balance provision, remove the French Victory Banner awards in the Special rules, make them to read
• The Allies gain 1 Temporary Victory Banner at the start of the turn for occupying each town Gross and Klein Wiederitzsch.
• The Allies gain 1 Permanent Breakthrough Victory Banner for every unit, excluding Cossacks, that exit the battlefield from any hex on the French baseline.
• The three town hexes of Möckern, the Tower and Manor form a Temporary Majority Group Victory Banner worth 3 Temporary Banners for the Prussians.
This should give the Allies more leeway to assault the towns (which typically entails heavy losses) before they reach what is currently an 11 banner loss cap.