True or false: the commanders at the Battle of Arausio came from different social backgrounds (one nobilis, the other a novus homo), which produced conflict between them.

True

Explanation:

Battle of Arausio took place on 6th Oct, 105 B.C. between Germanic tribe Cimbri and two Roman armies.

The two Roman forces were led by commanders Gnaeus Mallius Maximus and Quintus Servilius Caepio. Their internal difference and rivalry proved catastrophic for the Roman empire turning into their worst defeat.

Maximus was a 'novus homo' or new man who lacked the 'nobilis' or the noble background of Caepio belonging to Roman aristocracy. Caepio refused to serve under Maximus, resulted in an internal tussle eventually leading to their exiles and a massive loss of life and the battle.  

there is an explationation of this on a site called crash   course world history 1