Lances are awesome, just couch them and you cant be stopped!
Easy early money and renown imho^^ But Nord tournaments are nasty!

In khergit... yea, behind on the right is key. I like archery tho so i usually dismount for quick sniping.
Also, i always order my men to dismount for way better aim and to move together.

Always best to hold your own back five to ten seconds letting the enemy connect before your united front does :)