Dravida Ethnicity

Here's an interesting piece of trivia i chanced upon - the tamilian movie-star politicians, MGR, Jayalalithaa (extra 'a' owing to numerology), Vijaykanth and Rajinikanth are all outsiders. The tamil superstar, MGR is a mallu. Jayalalithaa is a kannadiga, Vijaykanth is an andhrite and as everybody knows rajini is a marathi. Add to this the fact that MDMK chief vaiko is an andhrite naidu. Puzzles me.