As I've mentioned before, my opinion is that I2a-Din is rather a representative of a Northern and North-Eastern (Pannonian, Dacian) population that was pushed further South and South-West by any of the barbarian incursions.
Perhaps you guys can come to an agreement or at least understand each other better if you simply say that "the Illyrii proprie dicti were indeed E-V13, J2b, and R1b predominantly, while their more northern cousins had more I2a".
Ps: I dont think I2a-Din is a Slavic marker at all. It's way too common among Romanians, Moldavians, and Vlachs (even in Albania) to be Slavic. Why would the ruling Slavs accept the identity and language of the nomadic highland Vlachs in such huge numbers anyway?!