Mount&Blade/Khergits

The Khergits have strong cavalry as well as horse archers. Their biggest weakness is a lack of infantry.

Against infantry
Your favorite opponent. Khergits horsemen and lancers should make short work of most infantry. Just set them to charge and watch the fun. You might also consider joining them as well.

Against archers
Lead your army using the F2 (follow me) command on an angle to the archers. If terrain permits, try to put an hill between yourself and the archers. Just try not to start a battle going uphill. If you have a choice between leading the archers up a hill to save yourself some shafts and keeping them on level ground, give the hill a miss!