Why does mass-produced cheddar cheese vary from package to package?

My question is about commercially mass-produced cheddar cheese sold in vacuum-sealed plastic packaging. The particular variety is a medium-age marble. I find that sometimes, when a package is freshly opened, the cheese has a firm almost crumbly consistency which cuts cleanly and easily with a dinner knife (which I prefer), and when I open a different package of the identically labeled product, it may be softer and somewhat gooey. The taste is also a bit different. I find that the cheese does not noticeably "age" after opening over a couple of weeks in the refrigerator, so it doesn’t seem as though it is a "shelf life" issue with the sealed product. For a mass-produced product, I would have expected a consistent product in every package.

What would cause the variation? Would there be batch-to-batch variations before packaging due to manufacturing? Is it caused by differences in handling after packaging?