Just the opinions of a novice, so apply other folks suggestions first.
Personally, I'm a believer in needing to suit the names to the fictional culture, that culture's applicable era, the story and so on...
In my WiP L.S., near future dystopian U.S., most characters have ceased using their last names, many their actual name, and are now using 'nicknames.' That works because the characters have intentionally had their past clouded, old standards and reasons for surnames are irrelevant.
In a long past written fantasy series I wrote, the culture a barbarian one... everyone in that culture had a singular name where the first letter of their name represented when they were born, based on a span of three-years. In other words, everyone born from 835-838 might all have a name with K as the first letter (ex.: Kaytoo, Korgewrath, Kuma, Kurta, Kaname', Kortme', etc. ). 839-842, L, and so on. The names were guttural sounding or melodious dependent upon chosen class... and other factors.
In contrast, I had a character who was a noble and the first of his kind (a politician) by the name of Korgewrath. In typical conversation, he was referred to as Grand Duke, or Grand Duke Korgewrath, or any of the typical modes of addressing such a person. Like what you're suggesting, however, when he was announced, initially introduced, or signed a paper, it read like this:
Grand Duke Korgewrath. Duke of the North & Western Realms & Markgraf of the Northern Wilderness of the Third Continent; Lord Protector of the Empire; Imperial Representative to the Elven, Dwarf & Barbarian Palatinates; Imperial Governor in Title to the Northern Second Continent and its Tre Land Bridges to the known lands; Patron Royal Ambassador to the Peoples Common. Most humble and willing servant of the Great Divine Emperor Most High, Stormbringer & his peoples... and yeah, he was a vain pompous jerk, hehe.
In my latest project taking place in the distant future (5k-8k years hence), the culture has changed dramatically. A matriarchal society, women are given a singular name. All men, however, are given a singular name and then as a surname, their position as born with their mother's name falling after. It is considered 'unsavory' for a woman to have more than one child by the same man (though that is changing, hence a culture clash is beginning). The woman bears the child, raises it for the number of years 'she' decides upon (typically 3-8 years), then hands off the child to the man who sired the child so they can learn his profession (and ultimately various others as apprentices to other women and men)... but, is expected to be brought back to the mother regularly so she can oversee their development.
As an example, the protagonist is named, Tarik Ska’Rahsch (first son, ka'=1). His mother's name is Rahsch. His father's name is Tranka Sta’Sename’ (ta'=7, seventh son of Sename')... Tarik's brothers and sisters named as follows: Kuma Ske’Rahsch (ke'=2), Seila, Canter Sko’Rahsch (ko'=3), Tulafae’, Aslace, Fanka Spa’Rahsch (pa'=4). Here you can also see that Rahsch prefers shorter names.
In that same project, another character bears the name of, Cugatalunaphae’ (Cugat) Sta’Tormareesa (ta'=7th)... Because his mother believes long names are preferable, everyone bore by his mother (Tormareesa) has a long name... and she has had 13-children believing in LARGE families. Cugat in the story has sired to date 26-children, each by a different woman. So, he must raise each and remember their mother's name and position based on birth to that mother.
Sound complex? Not really once you get into the guts of the culture, and it all has a point. Know also in casual conversation, only the first name would be spoken (applicable to what you're doing).
Point being to the discussion... You might have a long name or title, but, it wouldn't make much sense to require it be used in every utterance. Past that, just make up what fits your particular world. that's the tough part. You need to decide how your world's culture is, their traditions and protocols to determine how names sound and are used.
It sounds like you're part way there, but perhaps, need to define the supporting reasons and history a little, then they will come to you.
K2