The Alliance has the best combined naval force on the seas. Though the Ceruleans might dispute the claim, the combination of the individual effectiveness of their ships and the sheer number of vessels that the Alliance can field when it musters up the combined Crews of the entire nation make it a formidable naval power. Though the Cerulean navy might be more disciplined and effective in a ship-for-ship comparison, the Alliance would, if it were to call out all of its forces, be able to overwhelm them in a straight-up fight through sheer numbers and ferocity.
On land, Corsairs as a whole are only really fit to be skirmishers and guerrillas, not to meet anyone head to head in a direct large-scale battle. They have no standing armies, only fleets, and so when they are forced into a land-based conflict they depend on their marines, Divers, and Cazador Crews, none of whom are trained or particularly well-equipped to deal with an open-field battle. That being said, when they have acted as skirmishers and assassins in support of other nations’ armies, Jadefang Crews have more than carried their weight; drop a small Crew of skilled Cazadores, Divers, and Swashbucklers behind enemy lines and they can cause a terrifying amount of havoc before they eventually evacuate or are hunted down.
Individually, Corsairs tend to be warriors more than soldiers, intent on winning their own part of a battle without much concern for unit cohesion or discipline. This can cause problems when confronted with organized forces and shield walls, but their skill in skirmishing and hit-and-run tactics and their sheer ferocity in personal combat mean that so long as they pick their battles and maneuver around their opponents skillfully enough they can frequently come out on top.
Aside from the more martial and mercenary Crews and Flotillas within its population, the Alliance maintains a national navy consisting of three fleets, each commanded by an Admiral. (This is distinct from the Lord Admiral and Vice Admirals, whose positions are honorary Admiral offices and don’t actually grant them direct authority in the navy.) The Lord Admiral acts as the overall commander of the Alliance’s military forces, directing Admirals and recruited Commodores as needed to achieve the strategic goals of the nation.
The Fleets are treated as being national Flotillas employed by the Admiralty and the Lord Admiral. They are highly regarded by the everyday Corsair, and this mythic status means that they can regularly recruit the best Corsairs into their ranks. There’s an understanding amongst the navy that by joining the Alliance’s military forces you gain a share of the navy’s glory but also give up your ability to have your voice be directly heard in the strategic decisions made by your Captain, Commodore, and Admiral; a Navy sailor might still be able to speak with their Captain about the quality of rations or Grog on the ship, but they can’t expect to vote on where the ship goes or what it does, as that’s dictated by someone higher up the chain of command.
Mercenary Crews are a common thing in the Alliance’s official and unofficial military structure, taking coin in exchange for using their ships, personnel, and equipment to either provide protection, hunt down particularly troublesome people or beasts, or attack places (or ships) that their employers want attacked. Though the Fairwinds Edict makes the latter option a much riskier proposition if they’re caught, there are still quite a few Crews and Flotillas who offer their services to take out or steal from a target for the right price. All of these Crews and their rates are tracked by the Admiralty, and the Admiralty holds the right to hire them at their standard rate whenever there’s a national emergency that requires it, cancelling any contract(s) that they’re currently on in the process.
Swashbucklers are notorious for not getting along with the more-rigid-than-usual command structures of the navy, but their skill and ferocity in combat make their fractiousness worth putting up with. On a ship or the close confines of a city street they’re in their element, only needing to be let loose during a boarding action or urban assault to show their worth. Swashbucklers mixed in with the militaries of other nations are often used as skirmishers, taking out targets on the flanks of the enemy formation, or as lightly-armored solo warriors reinforcing a shield wall, darting out from behind cover to take advantage of an opening or to duel a particularly challenging foe.
The Cazadores are rarely involved directly with the Alliance’s navy, only being hired or having to deal with the navy’s command structure when there’s a particularly nasty beast that the navy needs help dealing with. Their strength lies in their mastery of stealth and skill in dealing with dangerous targets in small numbers — they rarely feature heavily in any kind of mass battle, but can be devastating when sent as guerrillas behind enemy lines or to eliminate champions or war-beasts that have been isolated from reinforcements.
Divers are a mixed bag; some of them are practically Swashbucklers or Cazadores, just with the skills needed to delve into Amethran ruins without getting mulched by the first trap or horror that drops on them, while others are their own brand of fighter, using armor, shields, and heavy weaponry to methodically take apart the defenses left behind by the fall of Amekhar’s empire. Because of this wide variety, each Diver Crew needs to be taken on its own merits, with the heavier-armored ones often being able to join a shield wall without too much difficulty, while the lighter-armored ones are often treated as skirmishers or assassins. The only real wrinkle in this dynamic is that Diver Crews are usually fairly small, sometimes as low as three people in a Crew — they’re often unused to functioning as part of a larger force, and this can mean that commanders dealing with an attached Diver Crew often end up treating them as an independent squad rather than a dependable part of a larger unit.