Generally early on my Russian army consists of whatever I can scrape together at the time, y'know?

Later on, I tend to specialize. My field armies are generally cavy-heavy (mostly HA's, preferably Dvor's), with my siege/city-taking armies consisting of plenty of cannon-fodder (Spear milita and so forth) backed up with a solid core of axes, musketeers and cavy.
Nothin' like the ol' 'UUUUUUUUUUUUUUUUUUURAH!' to make my day.