How to change paradigms of church and discipleship

Q. How can we change the current paradigm in the US of “Church” and “Discipleship”?
This question (asked in the June Challenge Survey) might be asked of just about any country in the world.
Let’s say you have a paradigm or idea or policy or practical thing you want all (or at least most) of the churches in an area to adopt. For the purposes of this exercise, let’s think of this as not an idea about discipleship but something simpler: “Churches should advocate small groups as a way to have more effective church life” (or some similar phrasing). How will you bring this about? It’s obviously not easy, but there are four possibilities:
Go for denominations: Many or most churches will be part of church groups ranging from formal denominations to loose associations to very informal networks. You can’t change a denomination and expect all member churches to change: some churches will leave denominations if they disagree with the decisions, while others will remain but simply refuse to implement new policies. Still, going for individual niches is not a bad idea, because there are some commonalities and agreements within denominations, and there might be more willingness on the part of individual churches to try something.
Go for big churches. Megachurches are growing, and the practices of megachurches often trickle down to small ones. They are more likely to have young people, and more likely to have more involved people. Possibly because of the independence granted them by their size and budgets, megachurches tend to have more orthodox beliefs than any other size and to be more evangelical than ever (and also more ethnically diverse). What would it take to find a megachurch that is generally friendly to the idea (small groups, for example), implement it, and then pass their success on to other churches?
Go for small churches. On the other hand, you could also try and find smaller churches interested in growing but needing a different model to do it. (Unfortunately many small churches fall for the trap of having the pastor or a handful of powerful people in charge of everything–those sorts won’t work.) Going this route might be quicker than trying to change a megachurch’s policy, and if the small churches are connected in an informal relational network, a highly successful model might pass virally between them.
Start over. Perhaps the most direct way to change the church paradigm, however, is to simply plant a new church planting movement. While this can be quite difficult in places where the existing church is well established, it can also be the path with the least baggage and internal resistance. (And remember, a movement need only double from 1 person 15 times to “take” the typical city in America, and 17 times to “take” 90% of cities.)