so if you look at these “Sons of Garmadon” you’ll notice there’s six of them, and the colors seem to correspond with the original ninja squad. Green for Lloyd, blue for Jay, red for Kai, black for Cole. The last two are a bit harder to judge, because there’s the one with a darker gray helmet with the light blue markings and a light blue shirt, and then there’s the other with a lighter gray helmet with blackish markings and a white shirt. The lighting in the majority of these shots aren’t very good as far as determining colors, but I’d say the white shirt one is for Zane and the light blue is for Nya.
The white shirt one is shown to be kind of a moron, and the green one is definitely the leader. The bit where they jump onto the bridge and the green one stumbles potentially shows that they’re not that skilled or never received training. Later when the green one takes off his power-ranger helmet, it’s shown that he has red glowing eyes.
As far as their group name goes, actual real life organizations that follow the convention of “Sons of ____” usually means that it’s members are direct descendants of those involved in a conflict, or it means that the members are loyal to whatever the organization is named after. The glowing red eyes are definitely giving me an Overlord vibe.