At the risk of calling for a no-true-Scotsman response, I do not know very much about Jainism, but a quick perusal does not leave me with the impression that its adherents are much less violent when they are in charge.
"His expansion of the kingdom, especially his annexation of the kingdom of Anga to the east, is considered to have laid the foundations for the later expansion of the Mauryan Empire." (https://en.wikipedia.org/wiki/Bimbisara)
"He forcefully took over the kingdom of Magadha from his father and imprisoned him. He fought a war against the Vajjika League, led by the Licchavis, and conquered the republic of Vaishali." (https://en.wikipedia.org/wiki/Ajatashatru)
"His expansion of the kingdom, especially his annexation of the kingdom of Anga to the east, is considered to have laid the foundations for the later expansion of the Mauryan Empire." (https://en.wikipedia.org/wiki/Bimbisara)
"He forcefully took over the kingdom of Magadha from his father and imprisoned him. He fought a war against the Vajjika League, led by the Licchavis, and conquered the republic of Vaishali." (https://en.wikipedia.org/wiki/Ajatashatru)