I can say that parrotfish are present everywhere on the Perhentian islands

Don't rent the cheapest equipment. Learn how to fit a mask and prevent fogging. Masks come in different sizes and shapes, and can be adjusted to your face. Rental places are often in a rush, so learning for yourself what to look for in a good fit, so it does not leak, is a good idea. A fogging mask is a real pain, because you can't see very well through it.