Headscratchers / Halo Wars 2

• How did the Spirit Of Fire's crew learn the name "Forerunner"? And how the hell do they know what a Halo ring is?
  • Isabel probably filled them in on the events.
• Why isn't the Retriever Sentinel that Anders gained control of at the end of "The Halo" used in "The Last Stand"? It surely would've given the UNSC a bigger advantage.
  • Considering how much fire was thrown at it during "The Halo" and how it was twitching at the end, it could have just suffered too much damage of Anders lost control of it.
• Why does Isabel go along with Cutter's plan to use Installation 09 as a beacon to Reach? Doesn't she know that Reach is destroyed?
  • I wondered the same thing. One explanation could be that depending on if it was in the same system or the same sector (there's a notable difference between the two) as Reach, the comms relay may not have been destroyed (if the former, the Covenant likely blew it up, but if the latter, they may not have known it was there), so if they send the Halo there and the beacon's still up, they can still conceivably reach out to the UNSC. Of course, the other issue is the Created, who probably shut down the comms network, and there's no way Isabel or the crew of the Spirit of Fire could have known about that.
• Why are the Sentinels friendly to the Banished in Awakening The Nightmare's final mission? In Hunters In The Dark, 000 Tragic Solitude went rampant and set the Sentinels on the Ark to target all living beings, including Reclaimers, which explains why they're hostile to the UNSC as well (unlike in Halo 3). However, in "Manifestation", they completely ignore the Banished and focus entirely on the Flood.
• What brought the Spirit of Fire to the Ark in the first place?
• In one of Isabel's PTSD flashbacks during, we hear a female scientist say "Unidentified vessel. Who are they? Isabel.", clearly referring to the Enduring Conviction. I know they're scientists but shouldn't they know a Covenant vessel (well, former Covenant) when they see one?
  • The ship might not have appeared in sight, but it may have appeared on scanners. Owing to how many years they spent battling the Covenant (and eventually the UNSC), the Banished may have masked/scrambled their ship's signature (in usual sci-fi fashion) to avoid showing up on scanners as a Covenant ship (since that could potentially cause a friendly fire incident or, in this case, alerted their enemies too soon.