just something done for fun (also non-leaderboard ranks only)
these are the uniform that i drew
the first three rank are probably just an introductory stage for new players that joined the navy for the first time
they can get quests from a dedicated npc introducing things like island capturing and complete it in order to be promoted from Marine to Lance Corporal, then Lance Corporal to Corporal.
the quests would just be short and simple so you can get the drip that you deserved 
going from Corporal to other rank would require you to gain fame as normal (Warrant Officer is just vice captain renamed)
the new rank, First Major, would probably requires 1.5 million fame (going by the main game increment) and the highest non-leaderboard rank, with the drippiest uniform possible 
is it necessary to add a new rank? probably not, but it would be cool
and yeah thats it, giving the current marine and vice captain rank a well deserved uniform as well as other rank with better uniform designs and drips