While this wasn't Operation: It's A Small World After All, it was planned with an alarming degree of precision.
And yet the timescale went to pot inside 2 minutes of reaching objective 1 (Magic Kingdom main entrance), because several members of Section #2 decided they needed the loo. The operation also suffered from mission creep ("Ooo, look, that ride we were saving for our second visit only has a 15 minute wait, let's do it now!") at least twice ("We could do Buzz Lightyear before we go") with the wrong personnel ("You do know your mother won't want to do that, right?), as well as random events ("Ah. Looks like the heavens just opened while we were in PhilharMagic", "Why is the queue for "it's a small world" four times longer than we expected?"), etc.
End result, we left the park 2 hours later than planned, hot and tired, and then spent 20 minutes longer than planned getting off Disney lands due to signage and map-reading issues.
This, folks, is what von Clausewitz calls friction:
“Everything in war is simple, but the simplest thing is difficult. The difficulties accumulate and end by producing a kind of friction that is inconceivable unless one has experienced war.
”Countless minor incidents – the kind you can never really foresee – combine to lower the general level of performance, so that one always falls short of the intended goal.
“Action in war is like movement in a resistant element. Just as the simplest and most natural form of movements, walking, cannot easily be performed in water, so in war it is difficult for normal efforts to achieve even the most moderate results.
“Friction, as we choose to call it, is the force that makes the apparently easy so difficult.”If something as simple as a trip to Magic Kingdom can't happen without friction getting in the way, when the most dangerous things we encountered are my mother-in-law, large American tourists with heavy backpacks and a Florida afternoon thunderstorm, why should we be so naive as to believe that a military action involving real bullets will go exactly as its commander wishes?
Why does this matter?
It boils down to the question: are you a gamer, or a wargamer? Do you claim to be interested in gaming for its own sake, or because you want to command a historically accurate force in encounters that bear a resemblance to what might have happened in real life, using authentic tactics of the period?
If the latter, I'm not entirely sure how you can without at least paying some attention to the concept of friction in your rules.
Now, does anyone fancy running Operation: It's A Small World After All using (say) Charlie Don't Surf?