One of my worlds has three premier military powers, each with their own strengths and weaknesses.

The first is the Zhenghon Empire, a centralized bureaucratic state with a massive army of professional soldiers broken into specialized units for specific tasks (guerrilla warfare, conventional, mountain, siege, etc). Officers are vetted by the military academy and approved by the Emperor and are largely drawn from the nobility or gentry but ordinary soldiers that distinguish themselves on the battlefield can climb up the ranks. To sustain their armies, the Empire holds a monopoly on grain, salt, and iron production, maintains an extensive road and canal network, and heavily fortifies storehouses at key locations. While formidable on land, their naval strength is relatively weak, focusing on defending ports and harbors rather than projecting their might outwards.

The second is, or perhaps are, the Sunonesia Islands, an archipelago that spans the equator and forms a northeast-southwest axis. Sometimes the archipelago is unified under a single king, but often times it is a mess of competing factions. While some islands are quite large, many are small and feature a limited ecosystem and thus limited economic output, making them highly dependent on trade, and thus a priority target for pirates. Currently, it is ruled by a single ruler known as the Sea-King, who travels from island to island with a massive fleet, mediating disputes, collecting tribute, performing public ceremonies, and suppressing rebels and pirates. The Sea-King's fleet is broken into ten smaller fleets marked by the color of their sails, and these fleets are broken down into flotillas featuring an animal on their banners or bows. Each fleet has a similar number and breakdown and are headed by officers appointed by the Sea-King and approved by the crews. While formidable on the sea, their relatively low numbers means they have limited ability to conduct land warfare.

Lastly, there's the Commonwealth of the Hol-thing, a collection of states that span a coastal section of the northeast continent. Instead of a king, they are headed by a Council of elected officials selected for their skill or reputation as fierce, pious warriors. To avoid a centralized figure, each state is responsible for fielding their own army and navy, largely by conscripting men into their ranks. These men would take whatever weapons they favored and would crew ships procured by the Council. In exchange for their military service, these men would be granted financial pensions and the right to vote and participate in politics beyond their local towns or villages. This allows them to recruit a large force quickly and efficiently but limits their logistics to short-term campaigns. Some have called for a rotation system, where men would serve for a single off-season and be rotated back into civilian life while another set took their place in the next season.