They thought the Pope would be in charge if a Catholic was in office.

I don't know about Usha, but I've known a couple of atheist-Hindu-Christians that viewed the pantheon like a list of aspirational metaphorical figures, and they just added Jesus to the pantheon.

Indeed, most xtianity sub-sects tend to hold to being exclusionary of anything else. So, while agnosticism and Hinduism might be accommodating, xtianity tends not to be. I'm pretty sure the Kirk kind of xtianity would be.

I’m butchering a 2 millennia story, but it illustrates how christianity fares in hinduism, and it even has some evidentiary support, so…

When the apostle Thomas was sent to India, he wound up in Cochin and began establishing a ministry or fellowship there.

He was frustrated by the lack of convincing required, or resistance to his ideas, without singular devotion.

The creator instantiating one more avatar is no stretch as Hinduism is pretty sophisticated in narratives, so Issa/Jesus just got added to the list that includes Krishna, and to this day you can buy hindu iconography with Jesus teaching compassion.

(Dude did succeed in forming a strictly Christian community though, and so arguably the oldest Christian sect is there.)

Did you read the article you linked?

Therefore, Samkhya maintained not only that the various cosmological, ontological and teleological arguments could not prove god, but that god as normally understood—an omnipotent, omniscient, omnibenevolent creator who is free from suffering—cannot exist.

In some ways people had got used to the idea that India was spiritual and religion-oriented. That gave a leg up to the religious interpretation of India, despite the fact that Sanskrit had a larger atheistic literature than what exists in any other classical language. Madhava Acharya, the remarkable 14th century philosopher, wrote this rather great book called Sarvadarshansamgraha, which discussed all the religious schools of thought within the Indian structure. The first chapter is Atheism – a very strong presentation of the argument in favor of atheism and materialism

Sounds pretty atheist to me.