The Tau Empire consists of many races, right? I read somewhere that the Tau Empire is something like 30% human now after expanding into territory that once belonged to the Imperium. So while the Tau themselves are nearly incorruptible, they have many allies who aren't. I think it's plausible that human auxiliaries could be corrupted to Chaos and bring some of the tech with them.
I just got my first model today for a Chaos Tau army, primarily using counts-as rules. There will be no biological Tau in the army, purely human auxiliaries and maybe kroot. I haven't been able to find any information so far on the warp presence of kroot, so if anyone could fill me in, that would be awesome.
The idea behind the army is basically fallen guardsmen with pulse rifles, plus lots of Tzeentch-corrupted machinery with tentacles and daemonic bits. It was inspired by the soul grinder model, actually.
Is this fluff viable?