The map+script provide minor variations in the initial map configuration, some initial units for a screening force, randomized (and changing) weather, randomized/context-dependent reinforcements, AI air and artillery strikes, and a little bit of "offmap theater" on your flanks.
The randomness should make the experience somewhat different every time you play.
Your initial forces and the reinforcements provide a variety of troop types that you cannot get with any single choice of commander.
The map is pretty simple, but may include a few things you find interesting if you look closely. However, most of the work has gone into the scripting. Due to the large combination of random and circumstantial events I probably haven't executed every line of the script in context, so if you try it please use -dev and give me a line number if scar bombs off.
If you extract it and look at the script, there is a huge amount of commented-out cruft showing things I tried that either worked or didn't. (Also, I was learning scar as I went, so hopefully my next map will have a much cleaner implementation.)
There is a companion summer map, identical except for the weather.
map at Steam workshop
edit: removed outdated material