The following three professions has a starting character be in the military:
- Soldier (Authority 1, Duty 2 for military; p.77)
- Mecha Pilot (Authority 3, Duty 2; p.75)
- Engel Pilot (Authority 3, Duty 3; p.73)
Authority has four ranks (p.94):
- 1: Low-ranking non-commissioned officer
- 2: High-ranking non-commissioned officer
- 3: Low-ranking commissioned officer or warrant officer
- 4: High-ranking commissioned officer
But what is the difference between low-ranking and high ranking? There are seven non-commissioned ranks in both the Army and Navy. The highest of these, SM of the Army and MCPO of the Navy are unique to the United States military of today. Going by that logic there's only one of each, making it not likely that a starting character starts out as the most senior enlisted soldier/seaman of the NEG military. This means that we have six ranks left, which splits into half nicely for three low-ranking non-commissioned officers:
- E-4: Corporal/Leading Seaman
- E-5: Sergeant/Petty Officer
- E-6: Staff Sergeant/Senior Petty Officer
And three high ones:
- E-7: First Sergeant/Chief Petty Officer
- E-8: Color Sergeant/Senior Chief Petty Officer
- E-9: Sergeant Major/Master Chief Petty Officer
As you can see both of these have a "central" rank on their own, meaning that Sergeant/Petty Officer and Color Sergeant/Senior Petty Officer is a fine middle point for Authority 1 and 2. Now, the issue is when you have several people of the same rank running around: multiple Sergeants (Authority 1) can work together in a platoon, but in such an organization they all command men themselves. As such, making them rank lower and have one be the E-5 rank officer works on a squad level. When you want to differentiate between the bunch you to establish a leader can either up the Authority quality by one point, or go for something like the Commendation Quality (p.94) and move the character up one rank.
Now, with the Mecha and Engel pilots it's a bit more complex. Commissioned officer ranks go from O-1 all the way up to O-10, at hich point you are a Field Marshal or an Admiral. If we split this one in half as well a low-ranking commissioned officer would be anything from O-1 to O-5:
- O-1: Second Lieutenant/Midshipman
- O-2: First Lieutenant/Sub Lieutenant
- O-3: Captain/Lieutenant
- O-4: Major/Lieutenant Colonel
- O-5: Lieutenant Colonel/Commander
So what O-rank would a Mecha or Engel pilot have? Mecha pilots are compared to "the fighter jocks of old" (p.75). The New Earth Government does not employ an air force as such; instead the navy is a bunch of flying ships. If we go by the same organization size as the modern air force however, a Flight Lieutenant (O-3) commands the smallest possible organizational size of the air force: a Wing of 3-6 craft. This would make an ideal organizational size for a party of players, meaning that them ranking below the O-3 leader of their unit would work fine.
Engel Pilots meanwhile are rare and require specific training, an implant and an unshakable will. This does not make them warrant officers though. In the real world skills in engineering, ordnance, intelligence, supply and so on are specialties for a Warrant Officer. Ergo, being able to maintain the alien cyborg deathbot would qualify one for being a warrant officer, but piloting one would not because that's not what warrant officers do. What Engel pilots are however is a bunch of highly qualified pilots who deal with dangerous and complex biomechanical horrors on a daily basis yet operate in a way similar to Mecha Pilots, which would in my eyes allow them to qualify for a higher rank. And the higher paygrade would be offset by A: the rarity of such pilots and something as simple like that is a simple sacrifice and B: the high turnover means that you won't have to pay this higher paygrade for very long. It's cynical, but not inaccurate. As such, I'd make regular Engel Pilots O-3 and leaders one rank higher.
- Soldier: E-5 for the squad leader, E-4 for the rest.
- Mecha Pilot: O-3 for the wing leader, O-2 for the rest.
- Engel Pilot: O-4 for the wing leader, O-3 for the rest.
The leader can be either one of the players or an NPC: this depends on if you can get players to go along with one being in charge or if they want more freedom.