That also sounds really interesting and I'd love to read more into it

Well I think you're right in that this is not a totally correct term theologically. But from the history I have read, they usually refer to Greek nobility basically giving up their practices of worshipping Zeus etc and switching to Buddhism in colloquial language as "converting".

I think there was a lot more interaction than I used to imagine. It was almost taught to us as if India was a semi-mythical place until the East India Company arrived. Now I know that there was cross-conversation and that the libraries of Alexandria were also filled with extracts of the Upanishads.

Now that is really interesting! Thanks for this.