Icon of Chaos Glory

I honestly prefer having an icon that would better suit you in close quarters so you don't need to worry about rerolling leaderships. Basically the IOCG means your already thinking about losing the unit. If thats the case, you should make sure the unit can't run away that easy by giving it more attacks, or better initiative, and so forth. I think one should be more concerned about winning the combat than worrying about retreating. Shooting is a different thing. You have good enough leadership anyway, and no one is that dumb to put their models out in the open in front of a bunch of fire power.

Anyway, thats my take.

Chaos armies are probably considered one of the most overpowered codexes in the game perhaps right there under Blood Angels.

I think its more about unit and point dispersion when finding a reasonable list. In that sense I could see why space marines and orks often come up with pretty good lists.