I think what Mad really does is that it simply adds all combatants in that fight, allies and enemies alike, to the list of "valid targets" for the mad character to consider. It doesn't simply make enemies attack one another. Mad enemies will still go for the most vulnerable targets, finish off whom they can, and try to maximize the efficiency of their attacks. If they see that they can finish off one of your party members, chances are they will go for it, even if that character is far away.
As for Taunted, it seems to just increase the priority of attacking the taunting character, but then you have no idea how effective that is, exactly. In one fight, I had Beast taunt an enemy and stand right in front of it. When it took its turn, it turned around and threw a ranged attack on someone else in my party who was on high ground and at a distance, ignoring Beast altogether. The way Taunted works clearly favors enemies.
As for Charmed, the problem with Charmed that I perceive, is that enemies seem to be much less effective with their attacks when they're charmed, compared to when they're not. I get the impression that they tend to waste a lot of AP on walking around.
Of course, when your own party members are charmed or taunted, more often than not they move with unholy cleverness and efficiency.
