You didn’t really change much about them as a whole. They are pretty much Whitescars but now they hunt anything. Would almost be easier, and better, if you said they were just Chaos corrupted White Scars. At least then they could be chaos undivided and could benefits from a lot.
I’m a Slaaneshi-bro so I’m down to give some suggestions. Why not make them so corrupted that they are now binding to their vehicles. The strongest ones of the warband could be totally fused with their bikes or w/e. You could even make Doomrider, pic related, your main Daemon prince. There is a audio drama called Master of the Hunt, which stars the White Scars as they hunt the Slaaneshi daemon prince, Doomrider...
“Through they tried to find the perfect prey, they became the animals they once hunted. Machine and man, neither was indistinguishable from the other. These were the warriors of the Lashes of Khan. For when their engines roared with fire, it wasn’t the mere sound of a machine but their screams for blood and the hunt that rumbled forward...”