Could you explain the starting positions a little bit more?
There are 2 player 1v1 maps (like Kholodny Ferma, Faymonville Approach, etc) and 4 player 1v1 maps (Semoisky Winter, Crossing in the Woods, etc).
So if you have fixed starting positions you also have to tell the players where Allies or Axis factions have to start. Here is an example of how it used to be for the last major event, Operation Charlie Fox:
Fixed positions (Allies in lower slots 1 or 1/2, Axis in higher slots 2 or 3/4)
In Best-of-1 mirror matches you can un-tick fixed positions.
http://www.coh2.org/topic/39043/operation-charlie-fox-official-rules
Your colleague ShadowDraft told me yesterday:
Until the rules are updated the mappick will choose his start aswell
That would work aswell of course.