High-level data organization advice for simulationist game

I am trying to scope out a game project, and I have a sort of high-level question about best practices or advice from experienced Unity developers.

I need to create a simple 'Risk'-style game that runs at all times within the play state. The game will need to consist of many factions taking turns, rolling dice, etc.

Each faction has several pieces of information which need to be stored (Name, color, army size, army location, etc, etc). Likely many more attributes than a normal game of 'Risk.'

It seems unlikely that on a large scale, with potentially hundreds of factions or territories, all of this information will be able to be stored in RAM. Therefore I am looking for recommendations on how you might go about 'looking up' this data. I have looked at XML and json integration, and also at more serious solutions involving sql. This solution would likely be used to save game data, too.

Any advice, even general, would be greatly appreciated. Thanks for your time.