They can't be combined into one because vehicles have a separate FOV setting and a separate base sensitivity. I could potentially rename "All" to "All Soldier" and make it known in the game notes that there is a separate calculation for vehicles.
A lot of different aims use the same sensitivity, this is a limitation of the game. This goes for the soldier sensitivity too, where 6X and 7X both use the 6.00x Zoom Aim Sensitivity settings, and 10X and 12X both use the 10.00x Zoom Aim Sensitivity setting. So when the same sensitivity is listed multiple times with a clarification in parenthesis, you have to choose which one to use. It's the same for in-game and config file, no difference there.
VehicleSensitivityDefaultTurret, VehicleSensitivityTank and VehicleSensitivityTransport are already in the calculator.
The others are either not used in BF2042 (like VehicleSensitivityCavalry) or not possible to add due to how the controls work (like VehicleSensitivityPlanePilot).