I really think exploring new regions isn't really a thing that should be limited to curiousity.

Faith - A crusade or missions to other regions,
Military - Invasion and patrolling,
Diplomacy - Go on a diplomatic mission to areas unknown, in search of support,
Luck - I seem to have tripped into this pool of water, which actually leads to a nation of merfolk.

That could help spread out Curiousity's power out.

The main problem I believe, is that Curiousity houses technology, and therefore civilization, AND it encompasses resources, one of the main purposes of the game.