Well equipped mounted archers.
Constant contact with the peoples of the steppe led the medieval Russians to adopt the tactics of mounted archery. While well equipped, they are not as skilled as they're steppe counterparts and cannot use shooting circle tactics. The role of these horse archers was to scout and harass the enemy forces before the main army engaged. Alexander Nevskii made good use of his mounted luchniki at the battle of Lake Peipus in 1242, where the Teutonic Knights found themselves outflanked and under a hail of deadly arrows from these swift mounted warriors.