Don't Front Dumbbell Raises Work the Front Delts Differently than Shoulder Presses?

[curling]

I have heard that if you do shoulder presses you don't need to do front dumbbell raises. Is this an absolute fact? Because it seems like to different exercises which would build different fibers in the delts.

The reason I ask is that I want the biggest shoulders possible but I don't want to overtrain either.

 

[sysopt]

shoulder presses hit the front delt hard, also uses some help from the lateral.