I checked and I was wrong about the spartans.
Now this doesn't quite make sense, and it probably screws with the canon, but listen in:
Noble 6 Stayed on Reach for the glassing, and was killed in the process. He knew that Reach was his home. He would not leave it. After he died, he entered some sort of a purgatory. This is where all spartans go when they die. You can not get out of the purgatory unless you die. It lets every spartan go down how they always wanted to. With a fight.
That would explain why all the other spartans were there, and why Noble 6 appeared to be in a completely random location. Although it messes up the canon by the helmet on the ground in the end, it's not that bad of a theory.
On another note: There has been talk about BOBs, a covenant ranger (i think). The description for them on b.net is: "Wipe them out". There is at one BOB on every level, but no one has found the one on Lone Wolf. Me, Phantasm, and CIA were seeing how long we could last on Lone Wolf, and CIA had this trick where you could hide under the spawning place and they would not attack you. We all hid there and then eventually CIA and 'asm got killed. I get bored so I go out to kill some guys, and then, after I kill an elite Zealot with a sword, I see a BOB running into a fence next to me trying to kill me. I did not attack him, I only laughed. Then I started getting shot by a spirit so I ran back to the hiding spot. He then leaves and goes somewhere else. Later CIA told me of the BOBs. Maybe, if I had killed him on legendary, it would have triggered the ending.
Then I went out to kill the 100000 elites sitting there and I just killed every one of em, then after a while I died. It was epic. I plan to make a video of it, put it on youtube, and set Linkin Park music to it.
The film