Just which setting of FOW is historically realistic or the closest to realistic. This has really been bugging me, so I conducted a series of experiments. I have just watched a Documentary on Austerlitz and read Osprey's clash of the 3 Emperors.
We have undisputed accounts in these resources of Napy's observation position, and what he saw from there.
Basically, from Zurlan, Napoleon, once the fog had cleared, using a spyglass, could see the progression of the 3rd and 4th Allied Columns, from their start position at the top of the Pratzen Heights and their progression down the Heights.
I used this battle, because we know for sure where the Emperor was, what he saw, and at what location he saw it. This way I could recreate the locations on the Austerlitz map and run the experiment in 3 modes. I fought as commanding both sides to enable me to place the troops correctly and toggle between Armies.
At 7:50am precisely, I took a screen shot of the French View and the Allied view. 7:50am is not historically correct but that is irrelevant, I had the Allies in March order and they moved faster than at the real Battle. I took the shots at 7:50am because that is the time from the French side that the Emperor first spotted any sign of the enemy
descending the Heights in "Gronard" mode, and all shots in the other modes are taken at the same time.
1. GRONARD MODE-Full FOW, view restricted to CinC
2. CONDITIONAL (historical delay), view unrestricted
3. MARKER info VAGUE (no delay) view unrestricted