Ah-ha, okay, I figured that it might be something like that.
Personally, I think I would be fine with the duplication, since the important thing for me is that the entities be in an "expected location" based on previous experience with the game. I really only like "new groups" when they all are part of the same "theme", for example I use the mods Schall Circuit/Transport Group (which adds recipes under a single groups for circuits and transportation entities), or Bio processing group which adds "organic" entities under a single resource group, because I think they group entities together according to a "theme" (like circuits, transportation vehicles, and organic materials). I don't think that "all of these entities are from the same planet" really jives with that, and the Factorio devs also don't break out the groups that way. I think it would be frustrating to think "oh I need an inserter", pop over to the Logistics group, frustrate myself because I can't find it there, and have to remember that it's actually in the Rabbasca group instead. Just my $0.02 though.
Don't get me wrong, I understand why you might be motivated to have this in its own group - I just personally disagree with that approach, so I hope there can be an option for this :)