If there is a place where Chaos Cults can be best represented it's in a Tzeentch roster.

The idea is to distinguish the four gods while staying within the bounds of what there is in Warhammer. I mostly stay away from AoS and I try to keep away from marauders. Nurgle marauders could get their aesthetic from Vermintide, not sure about Slaanesh. Bloodreavers and Kairic Acolytes from AoS would be nice for Khorne/Tzeentch marauders, the former having dual wield and two-handed versions, the latter having shield and glaive variants. If they do monogods it would be cool if they created different kinds of marauders based various sources. It would be kinda nice to have sort of gladiatorial fighters as Khorne's base troops.

Khorne Bloodbowl team in the first Bloodbowl video game had them. Haven't watched the video yet but I'm gonna say the marauders can be exchanged for Pit Fighter Cultists of sorts when it comes to Khorne. 2K A Total War Saga: Thrones of Britannia.844 A Total War Saga: Fall of the Samurai.