Biased little view you have Teeth. You are playing the most op build in strategus yourself. It's not the heavy cavalry that usually defines the outcome (I expect you're talking about field battles), it's more the hoplites and pikeman who does, but I guess you won't admit that? 
I have never failed to acknowledge the extreme strength of support polearms in Strategus, dunno why you would call me biased in that regard. The number of support polearms are usually quite evenly distributed across the two teams though, therefore they won't really decide the outcome. I think this is less so with cav. When the number of cavalry is noticably higher on one team, you really get to see the destructive force of heavy cavalry. When the war between Shu Han and The Coalition had just started, they managed to draw up some GK's and other cav, causing them to often have 15 or even 20 cavalry players. All of course on +3 Chargers and wearing +3 Corrazina armour. Even when defending a fairly closed village, this number of cavalry completely destroyed any infantry cohesion or formation on our side due to being too numerous to stop. I think you were present for a few of these battles as well. Of course we as a Byzantium led faction had a very good line up of support polearms, but yet we did quite badly.
When you actually manage to stop a heavy horse, half a dozen people turn around to kill the horse, while the rider sits up there blocking. When the horse dies, that means that there is usually a very angry shielder in the middle of your infantry group. If this happens a few times, your infantry will be completely scattered, fighting enemies that are running around them everywhere and all the support polearms get raped. I probably don't have to explain to you that support polearming is at its most effective when there are two somewhat linear formations fighting eachother.
When heavy cavalry charges and infantry charges are properly combined, heavy cav offers a huge advantage and can change the outcome. I am talking about the big picture here, not so much that heavy cavalry tops the scoreboards, of course that is the support polearm grinding points by killing their horses, but more their ability to completely disrupt an infantry group, giving an advantage to their own infantry group.
In these Shu Han - Coalition battles we got pwnd when they pulled of a proper wave, we even lost our spawns one time, and I dare say we outclassed them in the pikemen/hoplite field. Simply by parking extremely tanky horses and players dead center in an infantry group.
