The opinions of best researchers in the matter of the age of the Ṛgveda differed not by a few centuries but by a few thousands of years.
Source, in full
Ketkar, S. (Trans.) (1987, 19271). Maurice Winternitz’s A History of Indian Literature. Calcutta: University of Calcutta. (Ketkar 1987:270). quoted in Reclaiming Sanskrit Studies 03) Manjushree Hegde_ (Ed.) Dr. K. S. Kannan - RECLAIMING RĀMĀYAṆA. 3-Infinity Foundation India (2018)