is this common in your area? in my area, it is common for large stores to have horn/strobes and remote strobes on the ceiling in a checkerboard pattern.
I agree this is a common setup in big-box stores. More strobes are necessary in order to provide sufficient coverage throughout the aisles than horns. The sound from the horns can travel between the aisles, but the shelving blocks the light from the strobes from passing through.
In addition to a ‘checkerboard,’ I’ve noticed that a lot of stores in my area, especially those with very high shelves like Home Depot and Lowe’s, will have remote strobes directly over the long aisles, and place horn/strobes above the cross-aisles. This accomplishes the same purpose.