I don't know why I kept thinking this. I'm almost certain I even looked it up once before because I have a vague memory of being just as surprised then too. Anyway I keep saying Carmen Dei means Wind God. It doesn't. Carmen means song in Latin. 
Ventus means wind. I must have kept thinking Venti and it just stuck in my brain. Man if MiHoYo reads any of these they must have facepalmed so hard because this little fact reconciles a ton between languages. All the way back when v2.5 was just getting previewed I talked about this. The Chinese Constellations have a different pattern than the English. But actually it's not as different as I said because Carmen Dei means Song God. 
Geez so both patterns are similar in that only Zhongli has a Constellation related to his element. Rex Lapis means King of Stone and Lapis Dei means God of Stone. But now Venti and Yae who both have a sage Constellation 仙 are gods of something that defines them besides their element. Venti is a bard so song and Yae is a kitsune so fox. Now what that actually does - at least looking at the English - is that it definitively proves that Venti, Zhongli and Yae are part of the Original Seven. Only these guys have divine Constellations. It also means that kitsunetsuki or not Yae's Constellation relates to the Okami possessing her not Yae herself. Even if she was still in her Archon form the Okami's Constellation would be Divina Vulpes.
This actually almost confirms my theory that the Seven Sovereigns were the first intended Seven that Celestia wanted to use and so far we know that only Zhongli is left. In this case the Chinese Constellations will literally have king in the name and both English and Chinese will relate their Constellations to their element. We can therefore predict that their Constellations would go like this:
Geo Sovereign - 岩王帝君 (God King of Stone) - Lapis Dei
Anemo Sovereign - 烈风之王 (King of Gales) - Ventus Dei
Cryo Sovereign - 冰王 (King of Ice) - Glacies Dei
Electro Sovereign - 雷王 (King of Thunder) - Tonitrus Dei
Dendro Sovereign - 草王 (King of Grass) - Virentis Dei
Pryo Sovereign - 火王 (King of Fire) - Ignis Dei
Hydro Sovereign - 水王 (King of Water) - Aqua Dei
Notice the 王 in both existing examples for Morax and Decarabian. As for the remaining ones it's still entirely possible we won't even see these guys. It really depends on how important MiHoYo thinks it is for us to know about them. After all none of these guys are the current Seven anymore besides Zhongli. But it's still important to keep this in mind for another reason that I'll get to in a second. The other thing is I have no idea if any of the other Sovereigns were as respected by their people as Morax was. The 帝君 in his Constellation is an honorific for gods in Chinese. And as you can see from Decarabian's Constellation he wasn't a 帝君. His title should have been made before he decided to trap everybody inside his storm barrier. So that's why I only put the important part which is their element and king. Also you can see from Decarabian's title that the specific words are subject to change. For example the Pyro Sovereign could easily be the King of Flames 炎王. （炎 is often used to depict a fire element in anime. For example YuGiOH.)
Ok so there's another side to this. These Constellations would only apply to the "Sovereign" Archons that Celestia wanted for their Heavenly Principles. In my other other theory I talked about how Teyvat should have plenty of elements not just 7. Also Celestia wanted their representative Archons to be "pure" so each of these Seven would only have 1 element. But there could be tons of Archons that wield multiple elements and that might even be the natural state of Teyvat. And we have an example of this too. Andrius is the King of the North Wind or 北风之王. He wields both Cryo and Anemo. In other words all of these true Archons would have titles/Constellations with the 王 and be "sovereigns" too just not a member of the Seven Sovereigns. Example? 尘王魔神 the Lord of Dust Guizhong. This is the same as the whole Archon vs god thing only this time it only applies to these true Archons.
So if any of these first Seven Archons showed up with a sage Constellation we'd know that Celestia failed to subdue that element's Sovereign as can be seen with Decarabian and Barbatos. These guys wouldn't be allogenes though. They're something more like artificially created Archons. If that whole Thousand Winds business is accurate you can see that the way it works is like taking another kind of pure elemental being and empowering it to the level of an Archon where it otherwise wouldn't have gotten that mastery on its own. They aren't kings 王 of their elements but have been made adept 仙 at it.
Now the cool part to this. We know where the defeated Archons went after the war. If at any point we get to go to the Dark Sea we might be able to encounter them and that opens up a whole category of "sovereign" class enemies. We also might know what else are Archons. Maybe these were also true Archons so if at any point it became relevant we might see these guys become "kings" of their courts.
I can't believe I could have talked about this so long ago if only I hadn't made one stupid mistake lol 
Tips and Tricks from a Super Casual Genshin f2p
Commentaries on Genshin Impact and MiHoYo
PS: I don't own either of these guys so I can't check but did MiHoYo fix this yet?
If they didn't I feel better about making the Carmen mistake lol
