Remco,
The flag/system will be explained as a mechanism of the campaign.
The player should be instructed to simply move only one unit to only one VP/flag location.
If he wishes to move all his units to all three flags then he will get a decisive victory and he will receive as core force reinforcement the unit of the third flag (logic?).
Some info about the mechanism:
At the start of the battle all the flags will be under the NVA colors, this mean that the player will begin the battle with a decisive Loss at hand. So it is up to him to step on the appropriate flag and receive the points to score the need result in order to obtain the selected unit.
It is the same system with the secondary missions but here it lead to selected units!
cheers,
Pyros
p.s I will post a map 30x30 to show you what I mean.