In the last trailer from the movie Dragon Ball Super Broly, saiyans have Freezer army-like armors when they supposedly meet Freezer for the first time. How is this possible? Did saiyans and Freezer army got their armors from other race or is this a continuity mistake?
As per the release of the Broly movie, this is not a continuity error.
The Saiyans actually served King Cold before Freeza took over the empire. This scene is King Cold introducing Freeza to them as Freeza is beginning his reign. Thus, we can easily conclude that the Saiyans acquired this armor from King Cold when the army was still known as the Cold Force.