You are the person arguing that because you're allowed to pick up a pebble it follows that you are permitted to scoop up a handful in a bag thus by extension it's okay to grab a small bucket full thus it must logically follow that filling up the trunk of your car is acceptable therefore no one has any grounds to object to the dump truck and excavator that you've engaged to illegally mine gravel along the side of the road.
It's more like trucks are have been mining gravel from this pit for decades, and the courts have repeatedly affirmed that it's legal to one gravel.
I am not singling out flock here. I am merely observing that a given behavior having been deemed legal or constitutionally protected in one context does not necessarily translate over to another. Your previous line of argument justifying that the practices of flock et al are legal depends on such specious reasoning.
Then how is "the nature and scope" of Flock different? You didn't actually bother to explain what you meant here. In your earlier comment you emphasized that flock's aggregation is nationwide, which is why I was under the impression that is what you were referring to.