The title of the thread is a little off base. Well, more than a little.
Groups are broken. That is procedure. Can a mistake be made. Yes. Does it happen, sometimes.
Policy is that if another shooter is added to a group it is considered broken. We have seen an effort by a few shooters to "arrange " that they shoot together. We are aware of this and will do all that we can to clean up the situation.

You can help as well. If you are at a check station, volunteer to join one of these groups. You guys are mostly pretty experienced in the game. You know what is going on. Many of you know the folks in question. No big arguments or finger pointing, just help out. Heck, you probably will have a good time.
See you all in PA.
ken12