Unless there are other groups, a group is really not a group. In Statistics if a survey takes the entire 'population' into account then the Sample Set becomes the Population and the Population becomes the Sample Set. There is no differentiation, correctA?
Adhe maadhiri if there is just a set of people having one cultural disposition, and without the definition of religion as Westerners have; then it would not dawn on them to create a name. Naming comes only if one wants to differentiate, no?
In such an environment, they just had names for what we call now as Hinduism sects. Appo they were not considered as sects.