The "dog eat dog" world

It's a "dog eat dog" world, right? That's just how Western Culture is.
       I fly on United Airlines a lot, and I observed their "merger" with Continental Airlines. Actually it wasn't a merger, it was a takeover. Continental Airlines disappeared.
       I have a friend in Europe whose job in the corporate world is "Mergers and Acquisitions" between companies.
       This is all a form of Social Darwinisn, right? Survival of the Fittest.
       So here is my question: Does this apply to Christians and churches? You know, the "big gorilla" churches taking over the little guy churches. Is this a legitimate approach if a church's motivation is to introduce the most people possible to Jesus?
       It's got me thinking....