AFAIK you are correct, but there’s no reason they couldn’t have influenced/respected/reinforced one another’s beliefs over the centuries as complementary philosophies. OP asked about the surviving legacy of Greek Hinduism and as a practicing stoic I thought it novel at least to throw in my 2 cents

IMHO Stoicism of the Greek school is more or less Buddhism without concepts of rebirth or karmic weight, however the reward is a clean conscious and knowing your virtue is aligned with your actions which is essentially the same thing.