Why a separate key for Switch Targets (Vehicle)

[JemyM]

Can someone give me a good reason why this function cannot be assigned to the same button as the other targeting functions when thoose functions doesnt work while on a vehicle?


I am using a Playstation 2 joypad and frankly, I ran out of buttons.

Movement = Left Analog
Camera = Right Analog

Left Analog (Click) = Hud
Right Analog (Click) = Interact
Select = PDA
Start = Pause

Up = Medkit
Down = Change Weapon
Left = PLS
Right = Binoculars

Triangle (up) = Grapple
Circle (right) = Jump
X (down) = Crouch
Square (left) = Shoot

Top Pad Upper Left = Lock target
Top Pad Upper Right = Manual Aim
Top Pad Lower Left = Sneak
Top Pad Lower Right = Grenade

-edit-
Sure, I can reassign it temporary or place "pause" or "PDA" on the keyboard... it's just a bit annoying.