If you’re trying to create an exact replica of Diablo 1 then sure making a new model, animations, skeleton, textures, etc… then go for it though it will take a ton more time to do so.
Otherwise it would be far easier to use pre-existing GD models and either changing the texture/size of the model or perhaps grabbing something from Titan Quest since apparently that is possible (such as using the Minotaur or one of those larger satyr enemies?) and perhaps re-texturing those if that would work.