Hi!
Yes i would say AACW is the most "full featured" game of the three (economics, unit production...) and in consequence somewhat more complex than the other two.
As Prussian Prince explains, there is teh full game campaign (by far the most played scenario) in two versions,(starting in april or june 61) and then there are shorter full war scenarios with advanced starts (1862, 1863 1864).
Also there are a bunch of shorter "battle scenarios" (Shiloh, Gettysburg, 1 Manssas) that only last six turns or so.
The forum member Bigus has done another half a dozen or so of excellent scenario some are shorter Battle scenarios (Vicksburg, Atlanta, Kentucky camping) while other are intermediate ones that cover only parts of the map (Eastern Theater, Western Theater, Trans Missisippi...) and last for a year or so.
you have plenty to choose form
Cheers
PS: The WW1 game is very complex, but also a
completely different engine than the rest of AGEOD's games.