So it's the "Silver Timeline", and their reason for this divorce of real canon and actual Halo universe, is "to let both universe thrive and not collide."
Then I would ask you why in the hell did you call it Halo??? That doesnt like you're trying to create your own universe.
The show lacks depth, character development almost with everybody casted. 117 is not even close the badass killer all know. He's a hallow, weak minded being.