Agreed. Also note that the (Latin) Centum (pronounced Ken-tum) form has to be overall an older form than Satam due to the missing consonants and palatization n

Agreed. Also note that the (Latin) Centum (pronounced Ken-tum) form has to be overall an older form than Satam due to the missing consonants and palatization noted in the latter. The current thinking as far as I can tell is that Indo-Iranian (basically the ancestor of Sanscrit and Avestan) was the latest branch to break off of common Indo-European, though I think these models always oversimplify. The most archaic attested Indo-European language is actually Hittite, possibly followed by Tocharian.