Squadron Command
Three parts: an Order-target expansion, a new Order, and a keyword grant. Squadron Command adds Squadron to the list of units each Officer unit from your army can issue Orders to, and adds the On My Signal Order to those listed in the Voice of Command ability. On My Signal can only be issued to Armoured Skirmisher units: each time an enemy unit ends a Normal or Advance move within 8 inches of this unit, this unit can make a Normal move of up to D6 inches, and each unit can only move this way once per turn. The Keywords grant is what makes it work: ASTRA MILITARUM SQUADRON units from your army have the Armoured Skirmisher keyword, excluding Artillery units and units containing one or more models with a Wounds characteristic of 13 or higher. Read that exclusion carefully, because it is the whole balance of the detachment. Your Chimeras and Leman Russ tanks are Armoured Skirmishers; your Baneblade and your Basilisk are not. This is the faction's Order-economy detachment, and it is the one that actually contains the effect people wrongly attribute to the army rule: the Exemplary Officer enhancement below is what lets a single Order reach three Platoon units at once.