THe most annoying thing I've ever faced in a TW game is TW:W Chaos Chariots, Orc Chariots, Marauder Skirmishers, because the AI is very annoying with them, I assume it's doing something right
During my VC campaign the only way I had to actually kill Marauder skirmishers was to curse each unit
twice with curse of Bjuna, the Bats die to them or never catch them, the rest of the fliers have no chance in hell to outrun them 92-102 speed depending on tech.
And they do that thing where they outflank your lines WAAAAY too much and you have to constantly turn your camera around to see where the heck they are.
But you can tell it's almost scripted to do that because if you replay the same battle and camp in a corner the ai tries so hard to do that and it ends up squishing all it's chariots and skimishers in the border line of the map trying to reach you
I also noticed sometimes the AI will actually camp in a corner, not quite how a player would do it in a perfectly closed box but close, I wonder if it's using random terrain features that happen to be right at the corner or if they actually programmed the AI to do that sometimes when outnumbered!