This definitely comes from a level of hindsight more than anything else, but Rand flubbed his instructions to the Aiel before entering Cairhein.

Rand should have told the Aiel that despite the Cairhein’s failure to save the tree, they were still humans. And they weren’t darkfriends. As such, prior to the last battle, every single human should be considered as if they are the same Clan. The larger Clan of non-darkfriends ultimately to fight side by side to defeat DO and therefore even insults can be ignored. The only killing must be in self defense or the defense of another non-df. 

pretty sure that won't have worked as they mortal insulted the Aiel by desecrating their gift and that would've either caused a larger civil war or cemented all of them behind Couladin.