I still contend that the "Reforms" came about because of the need to have a standing army for operations outside of Italy proper, not because of some creative genius by the name of Marius. If there were no Marius, there still would have been similiar reforms. The key is the size of the empire -- which was becoming a problem. The "Reforms" were the solution.

The "trigger" was the annihilation at Arausio in 105 BC of a Roman army of 80,000 plus 40,000 civilians. This was a Roman army comprised of the "poorer classes" that had become the norm for that time in operations away from the homeland. Although poorer, these men were still not professionals. As Roman citizens, they were forced to serve and fight a foreign war that had little to do with the defense of the homeland (Italy proper). The lesson here has been repeated over and over again.