Just as food for thought:
The BGA scenarios were worked on for months and every scenario had, weeks ago, a detailed list of what units were portraying what actions, and where they were to go and at exactly what time. Every one was on a Powerpoint scenario except for Pickett's Charge. I will cheerfully send those Powerpoint scenarios to anyone who wants to see, and I will cheerfully recommend to any event organizer that everyone registered for an event should get one via email attachment from here on out.
The reason? Even though those Powerpoints were both emailed to top military leaders and made available on a "share site" with access, and were talked about in conference calls that went on for hours, the detailed plans did not get down to some brigade or battalion leaders. A half hour before one scenario, I discovered a key brigade commander had not seen the Powerpoint, was surprised by it, and had been given somewhat different instructions by his commander earlier in the day. I respect that commander, and I give the brigade commander a lot of credit for mentally shifting gears and getting his organization to perform well, but really, why wouldn't anyone want maneuver unit leaders to know the expected maneuvers? It's one thing for the rank and file and even company leaders to be in the dark and have to execute upon command, but at battalion level the focus shifts: That's where the leaders have to know what's expected of their organizations in order for everyone attending the event to have a successful outcome.
I sometimes run up against an attitude or philosphy that says "we can't make it come out right no matter what we do, so why try so hard?" The answer is that events where maneuver unit leaders see the scenarios and participate in walk-throughs turn out better than events where that doesn't happen, even if the final result is not perfection. The cost of doing that is simply time, attention and energy by fellows who are expected to spend time, attention and energy on behalf of their commands to make their experiences fulfilling.
There was a question in some minds, all along, especially with the Round Top to Peach Orchard scenarios, whether reenactors could even cut it, since some organizations had to be used in two different portrayals. It turns out, now as in 1863, the rank and file can do a lot more than some of their leaders expect. The sight of exhausted, sweating men pouring over a hill to fling themselves instantly into battle, after being engaged nearly three-quarters of a mile away and then asked to tromp across rough ground to do it again, was an unexpected period moment. That experience, for those guys, perhaps more closely resembled what a Union soldier went through on July 2nd than anything else we did. And I hope that when their feet stop hurting they have a similar realization.