Not positive but grey and mangrove may be different fish - body shape seems identical but mangrove has a distinct diagonal dark bar running through their"face" could be male/female or just a color variation not sure.
genuine red and silk snappers almost identical but silk has a yellow eye, both deep water, and great eating
Mutton Snapper is my favorite to eat and catch and dive with - they seem to have a particular "personality" all their own when you try to get close to larger ones and/or feed them