That's like saying baptists and Episcopalians are sects of Christianity and they're united in Christ with the aim of world domination. That is true, but it doesn't make the people who identify with these denominations unified or uniform in any way. And what it means to dominate the world with Christianity means different things to different people, and there are different methods for spreading the good word.
When you hear the song, "Hark the Herald Angels Sing," do you consider it a ode to world domination when it says, "joyful all ye nations rise, join the triumph of the skies?" Well, it is but that doesn't specify anything about what any Christian does with the message.