That does make sence but....
"“Halo Wars” takes place before Halo 1 during the UNSC’s first deadly encounters with the Covenant."
The
Covenant Human war has been raging for around 30 years! This happened
way befor Reach, or anything like that. And Judging by the spartans
armor, its not Mark V, the armor that the spartans were using Around
the time of the fall of Reach, So itmust be befor that time.