Hello, why can't these four DLCs be purchased separately?

Warhammer: Vermintide 2 - Warrior Priest Cosmetic Upgrade
[
Warhammer: Vermintide 2 - Sister of the Thorn Cosmetic Upgrade
]
Warhammer: Vermintide 2 - Outcast Engineer Cosmetic Upgrade
[
Warhammer: Vermintide 2 - Grail Knight Cosmetic Upgrade
]

I would like to purchase all DLCs,But these four DLCs cannot be purchased either in the game or STEAM
I am a pre order player, and I have also published a recommendation of 200+likes from STEAM. Can you help me solve this problem? I like the skin inside

You need to buy the DLC bundle if you want to get the cosmetic upgrade DLC, e.g., the Warrior Priest Bundle. Steam will automatically subtract the base DLC’s price from the bundle if it detects that you already own it. Check the total cost. If you already own the base DLC, you should be paying only for the “Individual price of the 1 items you don’t already have” (the Cosmetic DLC) modified by the bundle discount.