Merc vote accepted, yeah it's going to be medium. This would be set in 2186 CE, so after ME 2 but before ME 3, I want to be far away from the reapers and focus on the mercs. You have to be a Soldier or Adept, etc but you don't have to be human, just within reason (no hanar assassins or free-will geth).

Edit: 6-Man spectre groups would be unrealistic but we can always split it into 3-man groups with similiar objectives if people like the spectre idea.