> They weren't forced exist under a single political entity where one group was a substantial majority of the total.
See: The Mauryan Empire, various Khmer kings. The Kings were previously Hindu, converted to Buddhism with no conflicts arising from this change. There was no iconoclasm, no discrimination against Hindus, no mass genocide.
> [1]
See the main article: https://en.wikipedia.org/wiki/Origins_of_the_Sri_Lankan_civi...
In the entire article the word "Buddhism" is mentioned but once.
"Moreover, the British pushed for the dominance of Christianity and the removal of privileging Buddhism in the state government, the main religion followed by the Sinhalese"
> [2]
"Indians played a prominent role in the British administration and became the target of Burmese nationalists. Racial animosity toward Indians because of their skin-colour and appearance also played a role. Meanwhile, the price of rice plummeted during the economic depression of the 1930s and the Chettiar from South India, who were prominent moneylenders in the rice belt, began to foreclose on land held by native Burmese."
Literally nothing to do with their religion
> [3]
"After he seized power through a military coup in 1962, General Ne Win ordered a large-scale expulsion of Indians. Although many Indians had been living in Burma for generations and had integrated into Burmese society, they became a target for discrimination and oppression by the junta. This, along with a wholesale nationalisation of private ventures in 1964, led to the emigration of over 300,000 ethnic Indians from Burma. Indian-owned businesses as well as Burmese businesses were nationalised due to the so-called "Burmese way to Socialism". Many Indians returned and were given 175 kyat for their trip to India."
The common thread between your assertions are that one side is predominantly Buddhist and the other side is predominantly Hindu, however this does not mean the religion is the source of the conflict. Deeper investigation reveals in fact that the conflict was anything but religious. Nationalistic, linguistic, cultural, yes. But not religious. There isn't any bad blood between Hinduism and Buddhism the way there is between Hinduism and Islam.
Stop trying to manufacture a conflict between Buddhism and Hinduism where none exists. These two religions have coexisted for millenia in relative peace, unlike Islam and literally any other religion.