Cervical pillows are specifically designed to support your neck during sleep and help maintain proper alignment. The pillow should be higher where the neck will be and more compressed where the head will lay to guide your head and neck into the right angles.
Just like fingerprints, humans also possess a unique tongue print.
More pillows mean more comfort.
Overloading your bed with pillows to make it more comfortable is a myth. If you want multiple pillows on your bed, keep two to sleep on and two for decoration which you can use when sitting or laying on the bed to read.