As I learned from this game, Manual FCS is too clumsy to be useful with most weapons, especially at close range where rate of fire is very important.
One category of weapons however is almost totally unusable with automatic FCS. AA guns and AA ammunition weapons require manual control to use effectively. you need to be able to adjust the height and turn weapons at precise directions.
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There should be Hybrid/semi-automatic FCS to control AA guns and AA ammunition weapons manually, and the rest of a players' weapons more automatically.
To be specific it would be Automatic FCS that when you use the PRECISE CONTROL(default "SHIFT") to toggle between Automatic and manual FCS.
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Option A allow FCS to toggle between Manual and Automatic Configuration mid-game
Option B, allow AA weapons and ammunition to be controlled by manul aiming while other weapons are automatic FCS.
Option C allows you to use Automatic FCS, but make the precise actions only manual FCS can do, such as switching from front or back weapons, altering weapon height. For example the W key will raise the weapon height, Z will activate frontal weapons.