If you look at the 'stock' actors - you'll often see original gear and appropriate costuming - including saddlery.
The camera's focus is centered on the hero, who's dressed in a more 'dramatic' manner, while the sidekicks and bit actors are outfitted from wardrobe, without regard to a camera-grabbing look.
Look at Wallace Beery Jr. some time, and you'll see that he'd fit into any old-time photo with no problem.
Vaya,
Scouts Out!