Split commerce cart to multiple orders per product
As you now,by default drupal add to cart form add all products to the same order.

Looking at the code of commerce_cart.module, the base and unique behaviour of commerce_cart module, it doesn't works in other way. When a product is add to cart, the order associated will be the same order or a new order.

If you want to decouple the line items in two different orders in cart page you will have to code a module based in commerce cart with that feature.

You can take a look to this module, it maybe helps you https://www.drupal.org/project/commerce_cart_multiple