Buddha would be the the link between the various religion, Infact it would not be a stretch to say that there is a Proto World religion with Buddha as Central figure and all other religions and gods revolving around it
Mediterranean, Indian and Chinese worlds would seem much more closer due to Buddha being comkon in all their religions and Culture
Suddenly reminded of an article talking about Afro-Eurasia being called the "Ecumene" and imagining this Buddhist-Pagan wank timeline being about "the first world religion that united the Ecumene supercontinent with its various traditions and perspectives"