That order is the correct take. To find the publication order, by year, you’d have to look up the paper print anthologies and pair them with the pub date of the novels.
The order written was roughly:
Child of Prophecy (first appeared in Masters of Fantasy, Baen)
The Sundering Star (first in Undercover of Darkness, DAW)
Reins of Destiny (The Solaris Book of New Fantasy, Solaris)
Black Bargain (Evil is a Matter of Perspective) GrimDarkMagazine
The Decoy (Unfettered, Grim Oak Press)
The Gallant (novella, a temporary anthology bundle/ebook only/out of print)
The Gallant is now only available as e ebook from the Paravia studio shop (as all the rest of the Athera related fiction is also) and as Verrain’s backstory, it can be read at ANY TIME.
There will be a sequel to The Gallant coming, titled The Guardian - it is undergoing the fourth revision before final polish, but the finish date is not determined due to OTHER short fiction deadlines riding piggy back.
Other short fiction not related to Light and Shadows, but to the novel in progress, Sailing the Whirlwind (as prequel back history) are out now in print or coming shortly:
Wrong Man Standing - Unbroken, anthology to raise medical relief for Peter Orullian, printed by Grim Oak Press, out shortly.
Front Man Fallen - published in the April edition of GrimDark Magazine
Rogue Man Standing - nearing completion for turn-in to another charity anthology upcoming, look for the announcement.
These three ‘complete’ a trilogy of prequels that will be released in sequence and also, bundled and available after the rights revert back to me. (you have about a year’s wait, give or take). I will be working the artwork for them, and for Verrain’s sequel, The Guardian, during the upcoming year.