By looking at the details in the picture the two additional armored soldiers are more than likely Spartan 3's or could be O.D.S.T. with the updated Spartan 3 armor sets. But like I said with the obvious customization of the armor it is more than likely they are Spartan 3's that have been sent after the chief. Because of the rank of the officer in the picture (major?) it may be a black ops mission you are sent on at some point and time during the game or he could just be a random officer. Don't know but that is my take on what I see.
The lady to Chief's left is a Spartan IV, as she is wearing MJOLNIR Gen. II Armor, while Chief is wearing modified Mk. VI. The guy on Chief's right MIGHT be an ODST, I'm not sure. The officer on the far right is a Naval Lt. Commander (in the Army, a Major).
Well, the Women its the Lieutenent Palmer (Spartan IV) , the guy of de right is the Commander Tomas Lasky,protagonit of Halo 4: Forward Unto Dawn, and the marine i do not know, and Finally, the Master Chief
I didn't know her name until I looked at her render, and I'm pretty sure that she's a commander because that's what it said. When I saw the guy's name was Lasky I though to myself: No wonder he took Master Chief's side when the Chief and the Captain were fighting. Chief saved him all those years ago.