Yes the flag indicates the command you'll be given[brigade, division,corps, army]and the side. Some of the scenarios you have to play first before others.I really don't play them thru the stock scenarios. Mods don't work with the stock scenarios, you have to get the scenarios working thru the user scenario link on the main page then mods will work with them. It's not hard to do this and it is worth it because the mods make the game look better and makes it easier to play for new players [i.e. better toolbar, better courier system]. I'm mostly a WW2 gamer and i'm really enjoying this game. There is a demo which gives a fair representation of the game and there is some utube videos of the tutorials to help you decide. Any other questions i'll do my best with my limited experience with the game to answer.
Enjoy when you can, and endure when you must. ~Johann Wolfgang von Goethe
"Be Yourself; Everyone else is already taken" ~Oscar Wilde
*I'm in the Wargamer middle ground*
I don't buy all the wargames I want, I just buy more than I need.