Has anyone even read the FAQ's?
"“Halo Wars” takes place before Halo 1 during the UNSC’s first deadly encounters with the Covenant."
Like
i said befor, the Human Covenant war has been raging for 30 or so
years. UNSC has been involved for all 30 of those years, so if this is
of of the first incounters with the Covenant then reach has nothing to do with it!