Ahmedzai is a big Pashtun tribe in east afghanistan, why would they use the name Ahmedzai instead of their own dravidian name if they were the conqueror of Pashtuns and Baloch. For your info no Pashtuns tribe ever lived in Kalat so there is no question of defeating them.
Mir Suleman Daud ahmadzai the current heir of the Khannat of Kalat who is fighting for Baluchistan Independence, traces his ancestry to Ahmedzai Pashtun tribe. You should see his picture, he doesn’t look Tamil to me.