UNUSUAL RANK SYSTEMS IN FICTION

Because, if you want a story in a world far different from our own, maybe the ranks in the military (Church, religious orders... as well) cannot be that similar:

http://tvtropes.org/pmwiki/pmwiki.php/Main/FantasticRankSystem

Sardaukar military ranks in Frank Herbert's Dune universe.

• Levenbrech: Roughly in between a sergeant and a lieutenant.
• Noukkers: Officers of the Imperial bodyguard.
• Bashar (often Colonel Bashar): An officer a fractional point above Colonel in the standardized military classification. Rank created for military ruler of a planetary subdistrict. (Bashar of the Corps is a title reserved strictly for military use.)
• Caid: Officer rank given to a military official whose duties call mostly for dealings with civilians; a military governorship over a full planetary district; above the rank of Bashar but not equal to a Burseg.
• Burseg: Commanding general.

 The original League of Nobles titles in the Armada were Supreme Commander (Field Marshal), Primero (General/Governor), Segundo (Colonel), Tercero (Lieutenant Colonel), Cuarto (Lieutenant), Quinto (Sergeant), and Sexto (Corporal). 

A personal favourite of mine is the Calvarian hierarchy:

• The Calvarian army in The Reynard Cycle has one based on Old English:
• Each Regiment of ten thousand soldiers is commanded by a Latteowa, which we would consider a Colonel.
• Heafodcarls are equivalent to Captains of companies a hundred strong, assisted by a Lyftcarl, or Lieutenant.
• The role of sergeant is performed by a Prafost. 

• In Basic Instructions Before Leaving Earth, the warrior angels have a fairly simple rank structure:
• Soldier (ordinary grunt)
• Elite soldier (soldiers proven on the battlefield, act as commandos or unofficial sergeants)
• Lieutenant (commands a platoon of ~50 solders and elites)
• General (highest combat rank, commands all platoons comprising a particular mission)
• Seraph (semi-retired warriors, act as gatekeepers to Heaven and headquarters command staff)

• May Othello count as well, if we simplify it to the core?

General (commander of an army, governor of an outpost or province)

Lieutenant (second and aide to the general, a "Hand of the King"-similar role)

Ensign (third to the general, keeper of the regimental flag)

Noncom ranks in between??? Shakespeare gives First, Second, Third Officers. Do these fill in the gap?

Privates/soldiers/grunts

• A similar hierarchy to the one in Othello appears in my own Westeros AU Come Undone. Only that it's got more ranks, and it also differs slightly between the Allied Lands and the Westerlands. The latter system is more complicated, the Westerlands being a military state in the AU (a lieutenant, for instance, ranks lower in the Westerlands than in the Allied Lands). This is why Renly is far closer to Loras and Brienne (who just got promoted from ensign at the very start)... than his superiors are to Pod's alter ego "Ilyn Flowers".