The mockups/descriptions are vague enough that this is all highly speculative, but:
My main concern on Legacies is whether the AI will be able to track and correctly respond to/play around Legacy effects.
The Traditions mockup reminds me of Metaphor: ReFantazio's Royal Virtues. From prior description, I expected something more like the current level trees for heroes, except applied to factions? This system seems less versatile than that?
I think it would be cool if some Tradition choices were mutually exclusive. That is, I'm thinking like in World of Warcraft's system where some talents give an option between two abilities, and when you select one, the other is then impossible to receive. In particular, this would work well with the trait system for Brave, Intimidating, Etc.
As listed, it seems like the faction at hand is, Kraxis? Yithril? I don't think those traditions would fit Resoln well, much less any Kingdom.
I would lean more towards implementing the same as the current hero system, except for lineages, with each sovereign starting with some particular Tradition tree that's set at sovereign creation, maybe with four built in trees to start out with, and more possible via modding and/or future updates?