Westerners tend to make a big deal about what can be known.
While I fear that "managerial missiology" is a bit overblown, I do see it crop up a lot. Goals that can be managed, and for which funds can be raised, are very tempting.
They tempt us to pride in achievement and boasting when we are done. They tempt us into doing whatever it takes to get them done - to passion, to overwork, to "just do it", to hacking, etc. They tempt us to the idea that if we had "total knowledge" about the subject, the battle field, the thing-to-be-done, we could slice it up and manage the project to its completion.
Unfortunately, for many tasks, there are things that can be known, and things that can't. The whole methodology of Lean Startup is centered around starting a task for which much is unknown, and learning by exploration and doing (rather than waiting until total knowledge is had). Identify the biggest risks first, and test those. Because Lean Startup understands this principle of "things can't be known until we try things, until experiments are made."
The same is true of mission. There are many areas where we appear to have "total knowledge" - our lists, for example. And I don't say this to criticize a list maker, because I know the global lists and they do great work. But we must imagine that they are more accurate than they claim to be, and we mustn't imagine that more can be known than is presently known.
Knowing things requires study and reporting, and to know things below the country level requires a great deal of work by reporters and analysts that presently aren't there. Further, knowing things requires a willingness to report that, in current security environments, isn't always to be had. There's also the time it takes to report, which could be better used for other things.
What we need is to know enough to generally aim, and then use "explore/exploit" methodologies in regions and provinces and districts and cities and among peoples and languages to get us closer to the goal.