>>41214518Excess isn't simply debauchery. Excess of hate, excess of love, excess of violence. It matters not to Slaanesh, so long as there is no moderation.
Change is the only real goal of Tzeentch, he cares not from whence it comes or to what end, so long as it is Change. That is why his schemes always succeed, because they always work against each-other. His scheming has no goal save to change things.
The reason the Chaos Gods can't win against one another is because they feed into one another and destroy one another all in one go.
For example, in a single battle, Khorne takes delight in the Blood and Violence, Slaanesh in the extremes of Sound and Emotion, Tzeentch in the Ebb and Flow of the fates of combatants, and Nurgle in the Death and Stagnation that follows. In the space of a single combatant's death, Khorne delights in the spilling of their blood, Slaanesh in the pain and the ecstasy of dying, Tzeentch in the change from Life to Death, and Nurgle in the End.