The warriors of chaos feel like they take forever to upgrade their units with the warband system, playing a multiplayer campaign with a friend and after 60~ turns I think I've only actually upgraded 2-4 units of marauders to warriors (I've been careful to keep my unit cards and not merge units)

Is there something I am missing or are they meant to be something that takes a while to get compared to the daemons, who can start recruiting them en masse after 4-10 turns? (Depending on faction)

On another note, are Chaos chosen meant to be a sidegrade or upgrade to their warrior counterpart? As looking at them stats wise they dont appear to be all that much better seeing as they have their entity count halved

I did a little testing in custom battles (which I know isn't the best place for proper testing vs campaign) and they don't really feel all that much better than the warriors, which considering how long it takes to get them, feels off