I've been playing around with the 1805 Sun to Austerlitz scenario and it seems like there's a few problems with the scenario design. The historical campaign starts September 25th while the game's scenario starts October 1st.
The problem with this is that the scenario has the units pretty much starting in their 9/25 starting places instead of their 10/1 ones. Most of the French army that started behind the Rhine should actually be in areas east of the Rhine if the scenario uses a 10/1 starting date. This really puts the French player behind the historical eightball as far as the initial moves go for surrounding Mack at Ulm, despite Mack being fixed there. Either the scenario should start a week earlier on 9/25 or the French corps need to be moved to areas where they really were on 10/1.
The other big problem is the Italian theater where the situation is really what was happening on October 16th. Massena didn't cross the Adige and arrive in the Verona area until October 16th, yet we see him there with St. Cyr to start on 10/1. A more correct placement would have Charles at Mantua to start with Massena at Milan and St. Cyr probably at Piacenza. St. Cyr's historical role was to guard Naples against British intervention. Unfortunately details about this Italian campaign are rather thin since the main event around Ulm and then on to Vienna overshadow it's telling.
One big factor for getting the setup of units correct is the variable weather for turn 1. If the weather is bad on turn 1 the French player is really behind the eightball considering the setup snafu along the Rhine. Personally I think weather ought to be fixed to match history on turn 1 then let the weather be variable from turn 2 on. That way players aren't tempted to restart a game's start until they get the weather they like before actually commencing play.
It's probably too late to fix this scenario setup snafu for NCP but hopefully this will be corrected for NCP2.