The battles themselves also require far more tactics than most games it is not a matter of simply building masses of troops and rushing all at once. This means managing your vast, throbbing army is a breeze as you can easily select each formation from the top left of the screen. You can group them together into formations (for example, 200 Musketeers grouped together under a drummer and a commander) to act as one entity. So thousands of units on the battle field makes for quite a spectacle, and they are easy to control as well. All the units are individual, that is to say they are not automatically grouped together after construction. You make think that this would lead to immense problems of micro-management, but it really doesn't. Actually scrap that the unit cap is unlimited with the expansion, not that you would reach 8000 normally anyway.
Imagine Warcraft 3, "Ok quite a few units here - could be a bit more", now think of Age of Empires "Well this is a lot of units at once!" and finally any of the Total War games, "Surely this must be the pinnacle?" Well I can safely say that Cossacks smashes down those ideas and allows you to have upwards of 8000 units. So if the setting and graphics are good, what of the gameplay? After all, that is what makes or breaks a game.