One can accomplish a lot if they tell the people either convert or become slaves. I wouldn’t bank solely upon numbers.
Saying something to get someone’s attention is a lot different that slaughtering everyone in sight to make room for the railroad, and that is exactly what the Federal government did to the American Indian not much more than 150 years ago. Where Catholic missionaries, and other missionaries spread the gospel to the Indians, the Union Army murdered them wholesale. It’s much easier to get what you want if you just kill everyone in sight. This was not Catholic missionaries, it was the US Federal government. Mass genocide of an entire race of people.