medieval religoin
There was not a specific group of Roman philosophers. The Romans took up the philosophical schools of the Greeks of their time. The most popular ones were Stoicism and Epicureanism. Later Neoplatonism also became popular.
The stoics
the stoics
The Stoics
There is no official collective noun for philosophers. A "group" of philosophers is generally the accepted collective noun.
Cohort , legion or maniple .
One group would be called the Zealots.
monday club
decemvir
philosophers
The philosophy in question is stoicism. This was one of the two schools of Greek philosophy which became popular in Rome. The other one was Epicureanism.
The Evangelicals might be the group you're looking for.