My experience has been, having helped or been involved in a few products, is that most co-packers will not recreate Worcestershire sauce, but, they will use a commercial brand, not the store brand. For things such as butter, a lot depends on the market you are looking at. For higher price points, butter can and is often used, but, shelf stable and lower price point, you are likely going to be pointed to flavorings and oils in place of butter.
I'm feeling bearish, and I'm packing a Wusthof Grand Brisket slicer from MABA
"I'm Armenian...perhaps...but then again...maybe not..."