Halo 3 Achievements?

Imagine this achivement:

Managed to obtain a copy of Halo 3 on launch day. 1 million gamescore points(or whatever it is).

triple kill and overkill seems hard the rest is pretty easyJammaren

The only hard ones are beat the game on legendary and be a "spartan officer" (the reason I'm saying this one is going to be hard is that the first art for this achievement was the same picture as being a general in multiplayer, which is something like 500 wins and be level 50)