Sku’s for your store

I know skus are good for organization. I have a question for those that sell items from many vendors (like a gift shop or boutique).

I know that for small businesses that create all their own products (for example a stationary store creates all their products) so all their skus will be the same (JOU-SPR-FLO-YEL)

However, for those that carry different items from many vendors, all the SKUs will be different: Example: some items may have just numbers 1265.89 or a mix like JO-1276-SO

Do you create new SKUs for sorting purposes in your warehouse or do you input the vendors sku into the product?