[shatner]

One of the defining characteristics of Shinuyama and Jomon is how their recruit-anywhere troops and commanders are excellent and they have little-to-nothing they care about that is capital-only. Whether you want to continue that focus will impact what the design for their mages is like.

Here's my take on what a typical nation has
cheap h1 priest
better h2 priest
weak mage-priest (H1 + 1-2 paths)
cheap mage (2 paths max)
diversity mage (heavy randoms or lots of low paths)
ritualist mage (2-3 in 2 paths)
Capstone mage or priest (something awesome that defines the nation)

Now, not all of these slots are filled for all nations, and sometimes one unit covers multiple roles. Shinuyama has their amazing Bakemono Sorcerer to act as their diversity mage, ritualist mage and capstone mage. T'ien Ch'i has two cap-only mages which are both diversity mages (it's hard to get above a 2 in any one path with T'ien Ch'i)... however, T'ien Ch'i also has a super-cheap, super-efficient recruit-anywhere researcher with the minister of magic. It's really hard for me to point at which of those three is their "capstone mage".

For Jomon I'm seeing the following line-up:
some cheap h1 priest, maybe amphibious or ocean-themed
an amphibious h2 priest (UW transport, chance of getting W1)
five fold monk (same as LA Jomon)
Shugenja (same as LA Jomon)
Omnyo-ji (same as LA Jomon)

And then, we have the following if we want to emphasize Recruit-anywhere for MA Jomon:
Sendatsu E1N1A1F1 + 2.1xENAF, need not eat, 250 gold, map move-1.
This guy would be like Atlantis' King of the Deep or Pangaea's Pan: expensive, non-sacred and magically powerful. He's meant to be a mountain ascetic (like the Shugenja) but Master Shugenja was already taken so I had to fish around wikipedia for another, similar word. Since you'll already be able to recruit a W3+1xAA/EE/FF/NN sacred dragon from the ocean, I felt like having a water-less mountain mage (whose upkeep is the same since he's non-sacred) would help separate the two capstone casters. He also doesn't tread on the Omnyo-ji because of his complete lack of astral magic. He is cheaper than the King of the Deep or the Pan but the Pan generates freespawn and the King of the Deep has stats well beyond that of a flimsy, size-2 human.

If we want to emphasize Capital-only then we have the following:
1) Sendatsu E2N2A2F1H1 + 1.1xENAF, sacred, need not eat, map move-2 for 300 gold. Now he's almost a carbon copy of the Bakemono Sorcerer but not old, not an ogre and not recruit-anywhere.
2) Five Fold Yamabushi H2 + 1xAA/EE/FF/NN/WW, should have a magic weapon and decent stats, 200 gold, good for spamming one of the five signs, as well as handing him a crystal shield for smites/divine blessing/bigger five sign spam.

If you go recruit-anywhere then you won't need much in the way of recruitable sacreds (maybe the same Sohei and Yamabushi from LA Jomon). If you want to emphasize the capital then you should give them something good... though I'm not sure what that would be exactly.