Saying that Garleans are just hyur heads on elezen bodies isn't some "gotcha", it's just the devs deciding not to give them unique models outside of a few characters (Cid, Gaius, Zenos, Varis, etc.). It's literally the same situation as why Highlanders on The First have shaved eyebrows despite not having an Ala Mhigo to remember (with the exception of Ran'jit, much like the Garleans I listed).

As for the no "bad guy outfits" we have Odin armor, a primal of murder, and the entire Heavensward armor and weapon sets, and those guys were up to nothing good.