All saddles are shown with stirrups, which weren't used until 600 years later.
The Roman camps, even temporary overnight ones were constructed surrounded by a deep ditch, the earth removed used to build a bank upon which was placed a wooden palisade. This camp has no ditches, no bank, no palisade just a flimsy fence and large angular pointed logs as a barricade. These were seen previously in Britannia.
When using closed captions -- each time the Romans speak the caption says, Speaking Latin, but when the Germanic tribes speak German the caption says Speaking English.