Githyanki Ranks

Gish are actually a specific caste that both bladework and magic in veneration of Gith.  They don't directly follow the command structure, being specialist strikers like warlocks and psions.  A typical Gish should be support for a squad, thus commanded by a Sarth, but more powerful Gish should be assigned to a strikeforce, and be commanded by a Kith'rak.  Again, a Gish could also have a command rank like Sarth or Kith'rak 

I guess lower level sorcerers and psions are just basic githwarriors until they attain enough skill to be of real use in a battle.  This does kind of make sense, since all classes of githyanki can use martial swords.

Note I made "supreme leader" the lowest of the upper echilon offices.  A "supreme leader" is an honored title, but a common one, and like I said, in the original write-up of the race, a "SL" commanded a maximum of 30 troops.  In 3e and Incursion, levels and commands increased, and a Kith'rak (lvl12) was a likely command figure for a Planar Raider with 125 troops.  So for our purposes, a Sarth commands a small squad, generally about a dozen, but in some cases up to 50.  A Kith'rak commands a number of squads and a strike team of more powerful individuals.  A Supreme Leader commands multiple Kit'rak, so could be the head of an entire strikeforce of a thousand githyanki, or of a special-mission force of 20-30.

The upper echilon offices I kind of made up on the fly.  Asking for more cool-sounding titles.  I also want some unique titles for important figures in the Heartforce and Ascendancy. .... Regent, Herald, Nuncio, Chaimberlain, Catelin,  Supreme Castelin, Czar ...

EDIT of original post