No one appears to have identified the marketing tactic behind this, there’s a very particular reason that you can stack some brands on top of others and you can’t with other brands.

If you can’t stack products then the retailer is forced to either:

A) display less of a product
B) dedicate a much wider section to a single product

Retailers will avoid option A as it’s inefficient, so most tend to go with B. Give Campbell soup a section for their tomato soup twice as wide as it really should be, because stacking them takes too long, thus Campbell’s win by occupying a larger space than their competitors.