yes, that other option, and other factions access to mercenary, Capturing a gaia building in RM or Scenarios.edit1: i remember one thing, in Gaia that can be capturable buildings, the Mercenary have a Limit to Train in AOE 3, in Total War, map Campaign the available Mercenaries, are limit to numbers per territory, when all are exhausted, you must wait a time to all numbers reload slowly