For example, before anyone says that it's New & came out of nowhere, I fully expect to see that there is gonna be a Prison Warden in Mary Geoise & Jailers, similar to Impel Down, why? Because there are Jailer Fodders in Mary Geoise, (or similar to Prison Chief in Robin's Cover Story),
(Also don't forget that Doflamingo had Three Types of Armies led by his Executives, which further Hints that Mary Geoise/Imu also have Three Types of Squads, Knights are like Diamante Army who Specialize in Fighting Missions, while CP-0 are like Pica Army who Specialize in Commando Missions, meaning We still gonna see Team similar to Trebol Army who Specialize in Missions that require Special Abilities & They also handle Slaves)
Not just that, but don't be surprised if Underworld also have an Elite Squad of Assassins at their disposal, you think Oda created Assassins but those Underworld Emperors don't have access to Elite Assassins? And tbh They might end up as Cross Guild's Commanders (With Daz Bonez joining them if He wasn't already a Member)
Same thing for Races, whether Artificial or Natural, that's why We have Gorosei leading Imu's Demon Army,
That's why Seraphim aren't New Concept, because Pacifista's Existence since Sabaody indicates that there is gonna be an Elite Cyborg Squad,
And Minks indicated that We gonna have Inurashi/Neko Squad, and Sky People indicates We gonna have Birkan Priests & Shandian God's Guards ... etc
I'm not defending Oda here, but I'm explaining what Readers should expect to see, and not miss the obvious Teasers for them,
If an Occupation or Type of Fighters exist, then 99% there exists an Elite Team Version of it,
We got Introduced to CP-0, Seraphim, Holy Knights, Daimyo/Scabbards ... etc
Now We should expect to see next Jailer Squad, Underworld Assassins Squad, even Giants might have an Elite Squad,
If Final War starts & all Kingdoms of Giants decide to join the War, you think there won't be a Team who represent them all?
The fact that Elbaph King listens to Elders, and Giants have a Religion already indicates that even if They are divided by Politics, They are still United by Faith, and there is gonna be an Neutral Elite Squad who enforce the ancient law of Giants,
Sorry for long reply, but I just wanted to mention that Holy Knights are just the tip of the iceberg,
As a Writer, there is no way you create Concept of a Type of Soldiers, but don't think of how wd their Elite Versions be,
Edit: I forgot that Giant Squad does actually Exist, it's Galleila.