If it's not possible to get over the 'two goodwill' barrier with an exhibit, Runestone or otherwise, it'd be better to just bring on board the Arabyans to tip us over the 'one goodwill' threshold and hold off on a new exhibit til we have more to put in there.
It's not
always necessary to always try to get two Goodwill whenever we get one, but to run the numbers...
Let's assume that we put up the Runestone as an exhibit, on its own for lack of anything else to reasonably put alongside it. Let's also assume that we do this alongside Arabyan Scholars. Let's even
generously assume that when put up on its own, all the minor tags the thing has actually score. That gives us something like:
Runestone: The Tide of Skjold -
Centrepiece - History, Norsca, Asur, Khuresh, Magic, Religion
Central Themes: History 3, Magic 3, Norsca 3
Non-Central Themes: Asur 3, Khuresh 3, Religion 3
Awakening Interest: History 3, Magic 3
Sea Elves Interest: 0
Arabyan Interest: Magic 3
Luthor Harkon Interest: 0
Citadel of Dusk Interest: 0
Remaining Themes: Norsca 3, Asur 3, Khuresh 3, Religion 3
6+3+4 = 14 Interest
For reference, here's the exact score changes to our older exhibits:
Voyages of Haakon
Central Themes: Vampire 5, Piracy 5, Norsca 4
Major Themes: Age 4, History 4
Awakening Interest: History 4
Sea Elves Interest: 0
Arabyan Interest: Age 4
Luthor Harkon Interest: Vampiric Diaspora 5
Citadel of Dusk Interest: 0
Remaining Themes: Piracy 5, Norsca 4
4+4+15+3= 26 Interest (was 23)
Dangers of Lustria
Central Themes: Lustria 25, Trophy 15, Magic 5
Major Themes: Lizardmen 19
Minor Themes: Sea Beasts 6
Awakening Interest: Trophy 15, Magic 5
Sea Elves Interest: Sea Beasts 6
Arabyan Interest: Magic 5
Luthor Harkon Interest: None
Citadel of Dusk Interest: Lustrian Magic 5
Remaining Themes: Lustria 25, Lizardmen 19
20+6+5+15+14= 60 Interest (was 55)
So inviting the Arabyans is effectively +8 Interest on its own (not +9 since we were already getting partial value from Age on the Voyages), which jumps to +11 if combined with the Runestone. The Runestone is
optimistically worth +11 interest on its own, +14 with the Arabyans. Combined, we'd be adding +22 Interest, which is
exactly enough for +2 Goodwill.
...but it kind of feels like we're pushing it, there? It hasn't been explicitly spelled out just what makes themes count as Major or Minor. With the cut-down Voyages of Haakon, the Age and History tags qualified as Major Themes at 4 weight each, perhaps because we had multiple sources for each of Age and History. It might be the case that with a single relic exhibit, we just outright score the non-central tags as Minor Themes, but it also might be the case that they simply don't score.
When I pushed for the +2 Goodwill option for our Year 6 vote, I left enough margin for error such that the wiggle room wouldn't matter either way. Here, it makes or breaks the plan, which makes me slightly uncomfortable supporting it. I'd be more inclined to support a plan that simply grabbed the low-hanging fruit that the Arabyans represent (alongside the accompanying Goodwill), and then did some other acquisitions to guarantee a point of Goodwill next turn as well.
EDIT: Come to think of it... given the uncertainty caused by the wiggle room, this
might be an excellent time for a Learn or Research Relic action. It's plausible that we might pick up a couple points of Interest if we got more understanding of some of our existing Relics, and Research Relic specifically on the Runestone might add enough value to help us squeak by.