"Quid dubitas", inquit "Vorene? Aut quem locum tuae probandae virtutis exspectas? Hic dies de notris controversiis iudicabit."
Ne Vorenus quidem sese tum vallo continet, sed omnium veritus existimationem subsequitur.
*procedit extra munitiones*
This is Pullo talking, he is basically challenging Vorenus, and showing off at the same time. He's asking Vorenus to show off his courage and to basically prove why he thinks that he is worthy of being rank the first centurion.
Pullo shows off his courage by jumping over the fortification, to fight with the Gauls. Vorenus is left contemplating about wheather he should follow Pullo, so that he can show off his couage as well.
"...illum veruto tranfixum arbitrantur." The Gauls pierced Pullo's shield,and thought that he was dead, but the weapon did not pierce Pullo.
"Succurrit inimicus illi Vorenus et laboranti subvenit...Gladio comminus rem gerit Vorenus atque uno interfecto reliquos paulum propellit." This is showing that Vorenus is coming to his rivals aid, he is going to help Pullo because the Gauls are going to kill him. He kills one of the Guals and the rest of them back up .
"...in locum deiectus inferiorem concidi. Huic rursus circumvento subsidium fert Pullo." This quote shows us how Vorenus was now the one that needed help and Pullo was returning the favor.
"...summa cum laude sese intra munitiones recipiunt." After killing and pushing back the Gauls as much as possible, Pullo and Vorenus made a run for the wall. In the end it was very hard to tell who had won, between Vorenus and Pullo.