I would use Renown to determine "rank" in this case, and have the player with the highest Renown level (in the case of a tie, the highest TOTAL Renown) gain Battle Planning I. It's yet another thing that encourages players to spend Reputation and clearly designates who's in command
Problem is that would be a long term solution. They start as a Watch unit from the beginning, and all have the very same starting Reputation... I thought about this for a while, especially after buying The Blackcloack Watch. Even made the renown table which i will probably use.
3. Senior Patrolman
4. Watch Sergeant
5. Staff Sergeant
7. Detective Lieutenant
What i liked about stargate rules was that i wasn't so powerful, just enough to give a some edge in a very important moment. It wasn't intrusive...
Giving Battle Planning as is to me seems on one side too powerful (once every combat) and in the other side too limited (only 2 plans...). if the group really want access to this kinf of power, they should really think about one of them taking levels in Captain.
I'm thinking of using Wolverine Campaign quality(CQ, nice), but limiting the use to 1/Scene or Session, and allowing to choose any plan...