Before the two cross blades, Gannicus expresses surprise that Spartacus fought in the style of Dimachaerus. Unlike Gannicus, Spartacus originally fought in the style of Thraex and was selected to fight with dual swords after becoming Champion. Whereas when Gannicus was introduced in "Gods of the Arena", he was fighting with two swords before being named Champion.
Glaber doubts Ashur's claim that a single gladiator can easily defeat his soldiers if they rush him and he's surprised when Asher proves his claim to be fact. Glaber not only shouldn't doubt Ashur's claim as he sees this first hand from Spartacus in the first season, but Ashur accomplishing the same feat shouldn't surprise him as Ashur received the same training when he was a gladiator.