the Leaders are Generals: Some of them aren't Generals but like Doctors or something. Only a couple of them are Generals in charge of fighting etc.

the Legionnaires: Reserved for the fiercest warriors, a high honor to become a legionnaire. They aren't leaders but are apart of special forces as the elite soldiers. They can be attached to other squads, but there is a force full of legionnaires called the Legion. The Legion is the black ops, special forces. The best soldiers Terra Bellis has are in the Legion.

Commanders: They are in charge of special groups, or lots of ordinary groups. Commanders are usually called by the name Commander.

Group Commanders: That was what Eve was before becoming a Commander, they are in charge of a small group like Eves.

There are also Majors on the spaceship: They have the same rank as Commander.

The leader of the spaceship is the Captain.