hello sorry but my english is bad.
It’s perhaps possible to create sea in the world map with differents islands and harbors. If you have sea you have ships and news factions the pirates, you can attack the others ships or create news missions.
In combat you can include back attack, because it’s more realistic and strategic, if the enemy it’s back you, you can’t protect you with your shield. The strategy is different with heavy armor your are powerful front of you or light armor you have a great mobility to go back in your enemy.
The battle brothers can have a particular hability, RPG style examples :
paladin : good fighter against undead
thief : back attack is greatest
priest : give bonuse against undead and heal
beastmaster : good fighter against animal and beast
merchant : best prices in shop
ect…
News weapons :
gun powder powerful near but expensive, and long to reloaded.
fires arrows you can burns enemies and burns trees or others things can burns
exotics weapons : katana,sabre
siege weapons if you have plan siege attack ( fortress, tower)