Question - does each brand have their own manufacturing plant or is one plant used for many different brands? During the recall three years ago, I found out that one plant in Canada manufactured many different brands.
Unfortunately it seems to be a fairly common practice for a number of varieties of pet food to be made at the same plant regardless of what the brand name on the bag actually is.
The cost of facilities to make canned or dry foods seem to be a barrier for smaller companies to get their product to market at competitive prices. So often times these plants are simply provided product and recipies to follow by the smaller companies.
The real problem is many companies keep this information from the public and label it as "propriatary" until they have a recall. This is simply because they are afraid if consumers knew their $50 bag of dog food was made at the same plant as the $10 bag of alpo consumers might consider the alpo.
Wellness uses different manufacturing plants based on where the product will be shipped. But they do not tell you where your food was made.
6 years in retail tells me that is not always true all of the time about the rotation.
I can't tell you the number of times I have gotten home with some food (of the people variety!) and it was expired. 
