Okay, coming from somebody who has watched the entirety of new Doctor Who, and has played practically every Halo game, Spartans don't stand a chance. A Dalek's laser is a one hit kill on anything, no exceptions. Bullets, no matter what kind, have no effect on them, so the majority of the Spartans' arsenal would be useless. Dalek's can also fly, and while Spartans have Jetpacks, they have limited height and can only be used for short periods at a time. Meanwhile, a Dalek can fly nearly indefinitely. Finally, there is telling fact that Daleks have the ability of time travel, known as a "Temporal Shift". They could easily go back in time and kill Doctor Halsey, ending this foG before it begins.