Clue # 1
Out of the two of us, I am the most agreeable with our leader.
Clue # 2
I undertake a task off-screen.
Clue # 3
The aforementioned two of us have an identical physical feature.
Clue # 4
Unlike our leader, myself and my associate are only seen in one costume, one 'uniform', if you like.
Clue # 5
On both appearances, I physically interact with one or two of our heroes, and whilst I speak briefly, I do not address said heroes.
Clue # 6
Thank heavens all four of us were fit. Those Federation people were less of a match for us, yet we still ran away.
Clue # 7
It would be fair to say, my friend and I could be considered our leader's henchmen.
Clue # 8
I and my kind are located in one place, but there is another group of people located elsewhere.