I'm having slight issues with Missionaries in the America Campaign. When I finally am able to start building churches, I still cannot build extra missionaries. The church's description says it can support an "extra" missionary. That implies that I can get 2 missionaries per settlement. I can't build more than 1 per settlement, though.

Is there a way to get more or better way to counteract native priests that diminish the Catholic portions of my settlements? It's hard to begin converting future territories before invading when I have to keep my missionaries in my cities just to keep them Catholic. I only get a small number of missionaries whilst the AI get tons of them.. even my allies send priests to convert my cities.