I have to admit that with the Usurpers quest I actually had the impression that it may have been some reference to the Second Triumvirate of Rome:
Dolos is the equivalent of Lepidus, the weakest of the three known today for his scheming, disloyalty, and habit of backing Mark Anthony whenever possible. While part of the Triumvirate, Lepidus was formally the Pontifex Maximus (the highest priest in Rome) and before that was a close ally of Julius Cesar. In spite of this, the man was despised by many in Rome. Dolos lacks the military might of the Navy or Lion's guard, but he's very much responsible for rooting out disloyalty and internal threats, uses what power he has to manipulate things behind the scenes with the intent of turning
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Cayden into his puppet.
Also, it could possibly be argued that Dolos is also
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Brutus due to the implication that he intends to murder Adrana, in spite of the man's apparent trust in him.
Caden is
very much Mark Anthony. Anthony had become Cesar's most trusted ally, his second in command, and leader of a cult dedicated to Cesar prior to the man's death. It's also noted that Anthony more or less took ownership of Cesar's property and fortunes after his death, in spite of his will giving much of his wealth to Octavian/Augustus. At the time of Cesar's death, Anthony was certainly the most popular of the Triumvirate and by the formation of the Triumvirate he held the largest army in Rome's western provinces. Caden, by comparison, is explicitly Adrana's second in command, leads what is essentially a cult to the Lion, finds the possibility that someone other than him could take over after Adrana, and
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is later revealed to be allocating the vast majority of military acquisitions to the Lion's Guard over the navy.
That leaves Oxana Hyder as Octavius/Augustus. Funnily enough, (and not directly relevant to the comparison) Octavius was posthumously adopted by Cesar and made him both his primary inheritor and the one responsible for distributing the assets Cesar bequeathed to other people. Since Anthony (as stated above) took that fortune for his own, Octavius was forced to take out loans to meet the financial obligations Julius left him with. He also wasn't a military officer or anything at the time of Cesar's death, but a private citizen with no legal rights to command military forces. Why is this important to this comparison?
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Octavius used what funds he had to amass a private army that was later briefly used to fight Anthony before the Triumvirate's formation. This fits quite nicely with Hyder being forced to arm her fleet through the black market due to Caden abusing his position to get his forces the best toys.
This also gives another comparison between Hyder and Octavius: prior to the formation of the second Triumvirate, Octavius had no noteworthy involvement on Rome's political stage, much in the same way Hyder values the duties of her position over Caden's constant parading or Dolos' scheming. Likewise, Octavius and Anthony were almost constant rivals, much in the same way Hyder and Caden dislike each other.
And, well... I'm sure we can all see who Adrana would be in this comparison.
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Julius Cesar himself, naturally.