It only makes sense that this would happen. The number of shows is finite and the distance a corps can travel in a small amount of time is finite. For example, if on one day there are shows in California, Iowa, and Rhode Island, and the next day, there are shows in Nevada, Illinois, and Massachusetts, how many corps are likely to break away from the groups they performed with the previous night? It's just not worth it to go out of their way to change things up. (I realize that's an extreme hypothetical example, but I just meant it in an illustrative manner.)