Okay, this is what I came up with:
Inner Tracks:
2 - Goras (Earth, Sphere, Size E)
3 - Sharee (Earth, Sphere, Size F)
5 - Enderra (Earth, Sphere, Size F)
8 - Kayla (Earth, Sphere, Size G)

Outer Track
3 - Delora (Earth, Sphere, Size F)
5 - Celste (Air/Fire, Sphere, Size H)
7 - Aeron (Air, Sphere, Size G)
9 - Aguara (Water, Sphere, Size F)
13 - Orec (Air, Sphere, Size G)
14 - Mikturu (Water, Sphere, Size F)
15 - Dakordu (Water Ice, Sphere, Size E)
19 - Nemesis (Earth/Ice, Sphere, Size E)
38 - Shell

Does that sound reasonable? Can always tighten the orbits if that makes it too big again.