Just so I understand what you mean here--
Are you saying that only non-Trinitarians are true Christians?
Nope, it is just one of the best qualification to discern to identify true Christians. True Christians wont endorse persecuting anyone or killing is so against Jesus' Spirit.
It is just common sense. Jesus says we know them by their fruit. Violent faith is trinity churches fruit.
I use Jesus' word to discern what is right or wrong.