It's important to remember that theatres and amphitheatres are not the same thing. The item shown in this thread in Amman is a theatre for the production of drama, not an amphitheatre for blood sports and games. Theatres are D shaped, whereas Amphitheatres are oval. There are many more theatres visible than amphitheatres, particularly in the eastern Empire, as the Roman blood sports were not as popular in the Greek world.

I myself have currently identified 60 amphitheatres that are covered with good resolution. There are many more in the areas as yet blurred and many more underground and therefore invisible.