Reasons for the defeat of the Spartans?

In 71 BC, the Battle of Silar took place, where the army of Spartacus was defeated by the legions of Crassus, so the uprising was finally suppressed. The following reasons for the defeat of slaves can be distinguished:

1) A split occurred in the army of Spartacus, in connection with which the Gauls separated from the army of slaves;

2) The legions of Rome were experienced and well-armed.