i don't really care, but i do think that some positions do end up getting somewhat established, or at least universally acknowledged by the fanbase. like most ppl familiar with txt would agree that yeonjun's the best dancer and rapper, kai and taehyun are the better singers, etc etc
also plenty of groups do give positions like rapper, vocalist, dancer, etc, but don't define main or lead. nine.i come to mind as an example. also svt's hip-hop unit (s.coups, wonwoo, mingyu, and vernon) have confirmed that no one's the main or the lead rapper - all 4 of them rap. this doesn't apply to their other positions, though - dk and seungkwan are main vocals, hoshi and dino are main dancers, etc