What people often tend to forget in discussions like this one, just a few:
1) Those cavalry you see on top of the scoreboard are (with a few exceptions perhaps) all high level with all masterwork items. Now imagine a similiar two hander. He would be on top of the scoreboard as well. But the lack of awareness is a natural disease of two-handers. They spend most of their play-time on duel servers, and therefore dont understand battle very well. And those who do are always on top of the scoreboard.
Same for high-end rangers.
For pure shielders its difficult these days, they need to find a team that backs them up, so that they can focus on their thing.
2) Cavalry feed on themselves.
A good cavalry player (Oberyn for example) charges other cavalry to take them out of the game.
Cavalry players with no confidence spawn-rape to get at least one kill in a round. Those players would back-stab with a two-hander, or stick with the mob with a polearm. Its part of the game, actually its the core of battle. To find another way to kill a guy you cant beat in a 1 vs 1. For footmen you call it "teamwork", for cavalry you call it "overpowered". But its the same: cowardliness for the losing, cunning for the winning.
3) Rangers feed on cavalry.
Unarmored horses die in 2 shots.
But rangers are so stubborn, they rather shoot shielders on foot than wasting an arrow/ bolt on a horse.
4) Pikemen (and competent 2handers) feed on cavalry.
Sooner or later people will learn to carry a pike.
Maybe its time to allow to carry a pike in your pocket? Not very realistic, but swinging a huge axe like a pencil or feint-spam-swing-stab with a greatsword(and many other things) are physically impossible and are in the game as well, so why not sheath-able pikes like it always had been (and in native still is).
5) Remove horse-knockdown. Its ridiculious that an unarmored horse with the incredible speed of about 1 mph can circle around and knockdown a man in full armor. Some sort of stagger/ stun would be all right, but knockdown is ridiculous.
Riding your courser into a group of infantry should always lead to your death, no matter how competent the footmen are. Right now, I often see a guy on a courser lancing one footman, then bumping several armored guys (usually knock-down for the whole group) and escaping. Thats silly. I am thinking about a char with 13 shield skill on a courser and let the elephant return, this time as white one. Cavalry should do their cav-fights away from the infantry, then the winning side should support their infantry against the remaining foes. But as long as a courser (or destrier) is the best knockdown-weapon in game, why would exploiters change their play-style?