Miragaia is definitely a must have species.
Hesperosaurus & Dicracodon on the other hand seem to be very similar to Stegosaurus - so I my opinion they wouldn't be a good fit.
Some Stegosaurid species that I think might be nice additions to the game include:
Emausaurus: A species of thyreophoran from the early Jurassic period. Its fossils have been found in Mecklenburg-Vorpommern, northern Germany.
Scutellosaurus: A species of thyreophoran ornithischian dinosaur that lived approximately 196 million years ago during the early part of the Jurassic Period in what is now Arizona, USA. It is one of the earliest representatives of the armored dinosaurs
Scelidosaurus: A species of herbivorous armored ornithischian dinosaur from the Jurassic period found in the British Isles. Its fossils have been found in the Charmouth Mudstone Formation near Charmouth in Dorset, England. Scelidosaurus is currently the only classified dinosaur found in Ireland. It is the most completely known dinosaur of the British Isles.
Bashanosaurus: A species of stegosaur dinosaur from the middle Jurassic period recovered from the Shaximiao Formation of Yunyang, Chongqing, China. It is one of the most basal stegosaurs and is also the oldest known stegosaur.
Isaberrysaura: A species of stegosaurian ornithischian dinosaur from the middle Jurassic period that was found in Los Molles Formation of Patagonia, Argentina. The researchers have found fossilized seeds within its rib cage, which makes Isaberrysaura the first basal ornithischian to have a preserved meal found in its remains.
Yingshanosaurus: A species of stegosaurian dinosaur from the late Jurassic period. Its fossils were found in the Shaximiao Formation in China.
