Pseudo BS at best nothing more. faking things to suit agenda. Just last 2,500 years of recorded subcontinent history is full of one sided invasion from Central Asia with massacres, depopulation in subcontinent alone lol. Why would be history any different before that. When population was much smaller and concentrated around Indus , Punjab , Haryana region. Simple genetic markers can not be changed. This is not something unique to india alone , similar thing has happened across world.
Steppe region due to its geography, abundance of horses and nomadic lifestyle of people has been the most violent , powerful region for most part of Human history. as for claiming that nomads can not have a civilization and sophistication of a urbanite is pure fantasy.