Category v/s Category

When you have to come up with a brand name for a product, would you consider competing brand names as those in the same product category or from across product categories? In this day and age where the competition for mind estate comes from across product categories, it's an interesting thought worth considering. On the surface, it seems like a no-brainer. There seems no doubt in my mind that the only competition for name recall would be from other brands in the same product category. That said, I have a sneaking suspicion that information clutter affects brand choices across categories. For instance, if the 5 most important things on my shopping list are from across product categories doesn't that mean brand choice 2 in product category A is competing for mind space with brand choice 1 in categories B, C, D and E?