I don't insist on keeping it but it was actually on purpose, as I imagined the shields to be made out of stone instead of metal. I'm not sure about if I used parallax the right way though, you might want to check :)
Indeed. I was mentioning something similar with the Theban shipyards. And I've discussed with @Emacz how much less monumental the Spartans were compared to the Athenians. Having different models could also be useful for any mod that wants to include building upgrades (civ allowing), which I've also proposed for Towers. These things would make civs more unique, and make gameplay more interesting.
A stone theater was not built in either Sparta or Thebes until Hellenistic times. Prior to that, both cities had wooden theaters. The current stone theater/sanctuary model can be used as an Atlas object. For base game, half of the Spartan Theatron's cost could be in Wood.
@Obskiuras, would you like to create a concept?