This is one of PBR workflow what I knowledge and as an example for pipeline techniques/texture and quality. https://www.artstation.com/embed/5754916
Original concept art was borrowed from www.petesutherlandesign.com also I made some changes and added other details. This model can be reduced down for 3 LOD's and texture can be compressed. For example: 512 to 128, 2048 to 1024 and etc.