Lmao, you've literally just ignored over 100 years of scholarly consensus.
haha you bring only guns no bullets. You couldn't even make sense when you said, Dharmic religions. In your mind it's only Hinduism, but totally ignoring Buddhism, Sikhism, and Jainism. Nope they are not Indo Aryans. Rather there are no Indo-Aryans, from the beginning. By the time the IVC expired, the mix already happened between the people of the land and the people who migrated (Because there is no evidence anywhere for an invasion that happened).
Do you even know the Kambojas, Gandharis etc... were not the so called Aryan despite being the so called Indo-Aryans? They were called Yavanas. Why? Because first they don't follow vedic traditions. This whole Aryan thing was not at all based on race, because race, it is Black, White, Brown, yellow where white dominate, was a British theory. It holds no water in the vedic tradition.
All they do are compare relatively sounding names say, Indra a vedic deity with antra a Germanic deity, totally ignoring the fact that Indra was also called Satpati, Avasyu and many more. Why would one have many names, because it depends on the forms he took. Not divulging further into all that.
The Aryan which first finds it mention in Vedas, are a term used for Vedic group of people, this extended upto South India. By the way, these happened nearly 3000 years ago and the only evidence of it's existence are hymns. In short, the archaeological evidence of Indo Aryans is corroborated by an Oral tradition.