There are 2 real methods, as far as I can see, of making a portal hub. The current one would work if it is maintained. This type has a central location on one of the ring worlds and connects out to each of th other ring worlds from that main location. Each ring world then has access to the moon and home planets, as the current hub works.
The second type would work with nearest distances. For example, solum would have 2 portals, 1 to vulpto and 1 to epsilo. Vulpto would have 2 portals, 1 to Nasharil and 1 to Munteeen VI. Munteen VI would have a portal to Therka, and Therka would have a portal to Septerfon and the portal to Munteen VI, etc.
So it would look like: (And I’m counting each ‘side’ of a portal, but it’s only fueled once)
Andoweem: 1 portal to Vena V
Vena V: 2 portals, 1 to Andoweem 1 to Alturnik
Alturnick: 2 portals, 1 to Vena V, 1 to Nasharil (If this doesn’t wrap around to Munteen VII, otherwise, 3 portals and the last is Munteen VII)
Elopor: 1 portal to Berlyn
Berlyn: 2 portals, 1 to Elopor, 1 to Nasharil
Nasharil: 3 portals, 1 to Berlyn, 1 to Alturnik, 1 to Vulpto
Epsilo: 1 portal to Solum
Solum: 2 portals, 1 to Epsilo, 1 to Vulpto
Vulpto: 3 portals, 1 to Solum, 1 to Nasharil, 1 to Munteen VII
Septerfon: 1 portal to Therka
Therka: 2 portals, 1 to Septerfon, 1 to Munteen VII
Munteen VII: 2 portals, 1 to Therka, 1 to Vulpto (And 1 to Alturnik, if it wraps that way)
It’s all based on this map
I’m uncertain is this second way if more or less efficient based on oort cost than the first. If these charts are still applicable, that can be calculated, but I do math all day for work and hate having to math in games.
(Maps and charts are property of other players)