It's not the game that's broken or horribly unbalanced, it's the expectations of many of the players that are unbalanced. After reading so many threads like this, or of the "x is broken" etc. threads has made it painfully obvious to me that quite a few of the players on the forum (not necessarily players of the mod in general) believe that they should each be able to achieve some kind of demigod status on the battle field, being able to fight with no vulnerabilities for foes to exploit as they swing through the opposing team.
I've scrolled through so many posts from players whining or bitching about how their play style should be able to defeat cavalry, ranged, shielders and 2h/pole users that it makes me cringe. Mount and Blade was designed to try and retain some aspect of the real world in its game play, and just like in the real world no one path/style/attack/defense/etc. is absolute. Maybe I'm just crazy but it makes perfect sense to me that as a strict polearm user I should be vulnerable to archers, and that I am capable of killing cavalry, and that as an archer I should avoid direct contact and expect to be killed by charging infantry without support, or that as a cavalry player I need to avoid polearms and use my speed to flank and engage in hit-and-run attacks while avoiding faster riders. Doesn't this make sense to anyone else? And to clarify, I am not saying that the game should be designed so that it's just an endless game of rock-paper-scissors, that should be avoided at all costs, but that does not mean that the weaknesses and strengths of different play styles should be removed. If anything, I feel that the weaknesses of different unit archetypes forces players to be smart and tactical with their engagement on the battlefield, and to be a great player requires not only skill but situational awareness and knowledge of the restrictions of the various play styles.
But maybe I'm asking too much, maybe asking for people to be patient, calm and logical is outside the domains of the internet and the (or at least this) gaming community. I don't know.