^ A story being set in the past doesn't mean it's a flashback.
And having now seen The Sound of Thunder, it seems pretty straightforward that the proper sequential placement of The Brightest Star would be as a direct prelude to that episode.
As for Runaway, the only place it really fits based on the descriptions I've read of its events is between "New Eden" and "Point of Light" due to the fact that, from the latter episode on, everything involving Tilly is one continuous story up until the end of "Saints of Imperfection", and then " The Sound of Thunder" starts another pretty continuous story involving the hunt for Spock really kicking into high gear.
And having now seen The Sound of Thunder, it seems pretty straightforward that the proper sequential placement of The Brightest Star would be as a direct prelude to that episode.
As for Runaway, the only place it really fits based on the descriptions I've read of its events is between "New Eden" and "Point of Light" due to the fact that, from the latter episode on, everything involving Tilly is one continuous story up until the end of "Saints of Imperfection", and then " The Sound of Thunder" starts another pretty continuous story involving the hunt for Spock really kicking into high gear.