Yes, they should be hard to take on, but even in situation where heavy lance and war spear have the same chance to hit (spear the horse, lance the spearman) lance is superior as it's one hit kill where spearman need to stop good cav twice to kill his horse then win duel on the ground. Do you find fair that lancer have such advantage ? I feel it's very bad design.
I'm going to assume this is a 1v1 between a lancer with a heavy lance and an infantryman with a war spear or similar length polearm.
First of all, lets play out the lancer is circling an infantryman scenario. In order to get the sweet spot 90 degree angle on the spear guy, the horse is moving at a heavily reduced speed and probably will have a speed bonus that brings the cav guy to damage somewhere near, if not less than, that of the infantryman. If you manage to stop the horse (something that bad cav lets happen but pro cav rarely will in this situation) then that horse should be dead by your hand regardless of how little damage your weapon deals (this is assuming a horse less armored than the destrier). If its not, then someone interfered or you messed up somehow. Realistically, the infantryman rarely stops the horse in this situation. The easiest way to fight this horseman is simply to walk towards him while holding down block. Congratulations, you managed to defeat him. If the cav tries to bump-poke you then stop his horse and finish him. If he hits your down block then wait for the ding and then spam poke his ass.
Now lets assume that the lancer is taking the longer and more strenuous route of backing up in this 1v1 to gain some speed in each of his passes while charging our hero spear infantryman. Its all a matter of patience, really. Downblock that sucker until he makes a mistake, like getting off his horse to fight you on foot. Or maybe he'll try to bump lance, in which case you can stop his horse before he lances your face. Similarly, couching will get that horse stopped or killed because a 150 length polearm will outreach the couched lance.
If you ever find that a lancer is charging you and you dont have a pointy stick handy, downblock and jump out of his way, then spam at his horse's ass. If youre quick about it, chances are decent that on one of those passes, that horse will be moving too slowly and you just removed a nice portion of its hindquarters. Damage adds up.
On the subject of lancing vs. couching, I don't see why they would need to be balanced. The lance thrust is the lancer's bread and butter. Couching is a tool in the lancer's arsenal, the answer to infantry that thinks it can down block forever in an open field without paying attention to the lancer that wants to play. And I remember hearing wayyy back that a couched lance triples the damage that would have been achieved by a thrust, but that was back in vanilla M&B and probably has changed by now.
Making the war spear 1 slot isnt such a great solution, that would allow for lance and shield cavalry to take a war spear with them as well. And the war spear would become the one weapon just about every archer and heavy/arbalest xbowman takes with them as a backup melee.
