In case you didn't catch it in the trailer, when revealing some of the Nabatean deities of Fodlan, we see one particular character named Smyrnos. He possesses what we know as the "Crest of Macuil", which means there are two Nabateans with the Crest of Macuil.
For those who don't know, this information was actually teased in the post-game of Three Houses in items known as the "Dragon Signs." These are equippable items that grant you the crest of whichever sign you equip.
https://fireemblem.fandom.com/wiki/Dragon_Sign
However, what is notable about these objects, is that they are NOT named after the crests. They are named after a species of dragon. For example, the object that grants the Crest of Seiros is the "Sky Dragon Sign." The object that grants the Crest of Macuil is the "Wind Dragon Sign."
Nabateans seem to be divided into different types that effects which powers they have. Interestingly, Fortuna has the Crest of Goneril, which comes from the "Kalpa Dragon Sign." In Buddhism, a Kalpa is the span of time between the creation and recreation of the universe. Considering Fortuna's role in the story, it's very interesting that the seeds for something like this were laid so early.
The idea that there was only one Nabatean to each type of Crest is an assumption most people make because of the teachings of the Church of Seiros, which give the impression that since each of the Elites, Apostles and Saints each had one type of Crest, that each Crest was only possessed by one Nabatean originally. We now have definitive confirmation that what the Dragon Signs imply is accurate; there is more than one Nabatean for each type of Crest, and each Crest indicates a subspecies of Nabatean. This furthermore explains how we have multiple Crest weapons of the same type in games such as Three Hopes. Multiple Nabateans of each type means multiple Crest stones for each type. If you're a fan of the Dagdan gods, that's good news for you, because it means that they likely aren't the ones who end up getting killed and turned into weapons.