Okay, before we go on, I'd like some help deciding which Archons mainly belong where in the hierarchy and on which layer, so I can include them in the write-ups of the relevant planes.

Between Lunia and the Outside: Trumpets, since they are messengers, often go outside and are associated with Barachiel, the ruler of the first layer.
On Lunia: Lantern Archons: I'll connect the Lanterns to the stars of Lunia in my Lunia fluff.
Between Lunia and Mercuria: Here, we need some kind of first-line defender. Warden Archons, if nothing better comes up.
On Mercuria: Hound Archons. They are a good fit for Domiel.
Between Mercuria and Venya: ?
On Venya: Word Archons? Earathol is the clearest caster of the Hebdomad, so I guess throwing the caster archons here fits.
Between Venya and Solania: Owl Archons? Both Ascetic and Seer are connected to Wisdom, which Owls symbolize
On Solania: No Archon really says "Asceticism" to me.
Between Solania and Mertion: ?
Mertion: Swords or Justice Archons, see below
Between Mertion and Jovar: Sword Archons, if Justice Archons go one level down.
Jovar: Warden Archons are a good fit for Sealtiel, but they also make good first line defenders on Lunia.
Between Jovar and Chronias: Throne Archons? They are the highest caste, so they could easily get the highest level.

All canonical archons I know are assigned. We need at least four more types.

Wikipedia mentions a "Justice Archon" and a "Hammer Archon", both of which I don't know. The Justice Archon might be a very good fit for Raziel.