The Greeks and Romans were once the greatest warriors of all time but you see where they stand now. Even you guys were ruled by the Palas and Magadhs who were super good at warring but now you aren't seen as a powerful militiary force. So digging about Cholas being great warriors in the past and southies being subjugated isn't a logical debate. You've quoted Germany and France where they did good both economically and militarily but TN isn't a separate country, what it's leaders really care about is economic development which it has done well while the centre takes care of the military
The thing is if you dig the histories of Greece, Italy or even Bangladesh, they have never been subjugated by a foreign power for long. All these countries are now proud independent nation-states, inspired by their glorious past and continuing its legacy. This feature is something absent among the Tamils.