The consensus here seems to be that "grouped" means physically present in the same pipe, disconnect or panel. It does not mean twisted or touching.
As someone pointed out, you can have 20 third graders in a classroom. They are grouped. They don't have to be touching, twisted together or anything other than present in the same space.
The intent of the code is to prevent undue heat. Having your hots & neutrals in the same pipe, disco or panel accomplishes that. The code is complied with the way it's always been done. There is no need for outrageous interpretations.
The code even defines the space as " ferrous metal enclosures or ferrous metal raceways".