We see the same thing in the US for matresses, appliances, and especially electronics like TVs. Even well known large brands will be sold with long, and different, model numbers.

The B&Ms know that people are comparison shopping, even as they browse the store: they'll be on their phones looking up model numbers to compare to online and at nearby stores. As we all know, a moat is preferable to competition, even if you have the same or inferior product.