Capacity of 10,000 is nonsense.
Why? The Coliseum could hold 50,000--more by some estimates. The earlier Greek theatre of Argos had a capacity of 20,000. The 3rd-century BC theatre at Ephesus had a capacity of 24,000.
“To meet this demand, the Roman Empire built massive theaters, many of which were capable of holding 10,000 spectators or more at one time. Roman fondness for plays explains why nearly every city in the empire contained its own theater.”
https://architectureofcities.com/roman-theaters