Making Mata Nui Island

I'd like to introduce a project I've started that I'll hopefully continue through completion. I'm a skilled blender artist, and I want to use those skills to make the most graphically impressive mata nui I can make. I know how to texture it, model all the little Koros and fill it with foliage. I'm starting with this depth map provided by Mr Faber. It's a bit lo-res and I heard he used world machine to make it. Maybe I can find a better approach through sculpting. Here's a link to my demo reel(soundwarning): https://drive.google.com/file/d/1TGbW56UFDTaohnO8qBodsnDhvxR03xQZ/view?usp=drivesdk