So, we have buildings in the desert that look like the Fighters Guild, act like the Fighters Guild, but sound like temples and are called Fighter Trainers on the map. As discussed in a topic on the General forum, the existing head canon is unconvincing and the optimal technical solution is proving elusive.
Therefore, I decided to write the text for a book item that would provide a more detailed and interesting explanation. It adopts the basic claim from UESP that the buildings are linked to Ebonarm somehow, but goes in a different direction that also explains the absence of Ebonarm's name at those buildings and the existence of Ebonarm shrines in other regions.
I just need someone to convert the text to Daggerfall's book format and package it into a mod. The item is intended to be available on bookshelves and loot drops. The text is within the spoiler tag below.
Spoiler!
Citadel of Exile
by Sordrak Noshryne
The desert regions of northern Hammerfell have undergone a drastic change to the pantheon. The cautionary lesson emerging from these events may be disregarded at one's jeopardy, hence the grateful author's petition to the School of Julianos for broad publication to Tamriel. Consider the following question and please refrain from answering now. Are you loyal to the sovereign of your home or the Divine of your heart? Pray that an exclusive choice is never thrust upon you.
As the Divines are represented on the mortal plane by temples bearing their names, so too is the God of War represented by the Citadel of Ebonarm, albeit in hearts and minds alone at the time of publication. It should be no surprise that Ebonarm also leads a templar order, his most recognisable influence in human form today, namely the Battlelords. As Dibella's interests are misconceived by the uninformed as mere figure and fashion, so too is the God of War misconceived as a warmonger. His former stature was indeed inspired by his peaceful intervention at Oelander's final battlefield.
Ebonarm's alliance with the Fighters Guild is one of mutual benefit alone. Some of the highest-ranking adventurers in the Guild would join the Battlelords later in life, having decided that wealth and fame were less meaningful after all. Meanwhile, some of the greatest trainers in Hammerfell had learned their skills from the Battlelords and joined the Guild to make a more comfortable living. This relationship would become vital to the survival of the Citadel in recent years.
The War of Betony was a turning point in three ways for the Iliac Bay, one of which is a question for a fellow scholar with greater insight. It was a humiliating defeat for the proud Redguard warriors of Sentinel. It was also the spur for the Kingdom of Sentinel to persecute Ebonarm's followers.
The late King Camaron's family tradition ensured that the warrior's commitment to strength and courage did not escape his comprehension. It is also beyond doubt that he deemed his authority compounded by skill in personal combat to be worthy of Ebonarm's respect, unless a fellow scholar can demonstrate the hand of Sheogorath in the actions that followed. It is not so easy to impress upon a strident man of action the subtle virtues of patience and stoic temperament. Thus, Ebonarm's willingness to endure Nocturnal's taunts had likely flown over the King's head as surely as a pair of ravens.
The Citadel had been wary of the King for many years as they remembered the unconcealed disdain for his eldest son, may he rest in peace, for having a sickly body incapable of upholding the family tradition. There is no shame in Ebonarm's eyes for a boy that nature forbids from a warrior's armour. Becoming the best of ourselves with what we have can be as pleasing as strength and courage combined. The King's reaction to the young Prince's death may have earned a smile from Boethiah instead.
Thus, a declaration of war from the same father would provoke a devout conscience to objection. Betony is a distant island in the Iliac Bay, populated by Bretons who cared only for safety from pirates attacking their fishermen. The possibility that the King of Sentinel's territorial claim may have been legitimate only raised more doubts about his righteousness, for he did nothing to mitigate, let alone prevent the pirate attacks on Betony. His newfound sense of responsibility for his alleged protectorate only emerged when the King of Daggerfall intervened.
The prayers of the Citadel to stop the War of Betony became common knowledge and were taken as sedition. King Camaron swiftly decreed that devoted followers of Ebonarm were to be detained on sight and their temples closed. He also pressured the neighbouring regions in the Alik'r Desert to do the same. In a rare diversion from their mercenary ways, the Fighters Guild defied the decree and assisted many of the Citadel to escape persecution. The King's wrath was narrowly averted by supporting his war effort for a lesser fee.
The end of the war made a widow of Queen Akorithi and internalised a common resentment that may persist for a generation. The people wanted someone to blame within reach of their outrage. Now appointed as the regent of Sentinel, Akorithi saw fit to scapegoat Ebonarm for the disasters of the past year. She was preparing to order the complete destruction of every temple site when the Fighters Guild petitioned a compromise of mutual benefit. The land would become Guild property and the buildings would be repurposed as Fighters guildhalls, thereby replacing the defiant Battlelords with malleable mercenaries. Sentinel's beloved Princess Aubk-i, soon to be Queen of Daggerfall, persuaded her mother and her mother's subjects to focus on rebuilding their strength, rather than burning their cities.
Ebonarm's diaspora is spread far and wide, welcoming visitors to their aptly named shrines, determined to slay the wave of despair and defend the hope for building a better future. Are you loyal to the sovereign of your home or the Divine of your heart? Pray that an exclusive choice is never thrust upon you.