[dparm]

For the most common maintenance items, there can be multiple suppliers at once such as Mann and Mahle. The parts are functionally identical but sometimes the packaging or minutia can be different. Similarly, some of these big OEM suppliers have multiple sub-divisions as you alluded to (Wix, Hastings, Baldwin, etc).

In the end, as long as you buy from one of the big OEM suppliers, you should be fine. I have used a variety of those brands over the years on my BMW and on previous cars and there has never been an issue with fitment or performance.