Generate gameObjects from Data

Dear everyone,

I am currently working on a project with Unreal 4.7, the game is designed as a on-line/hot seat turn based strategy game for Mobile/tablet. At the current stage, I am working on a prototype in blueprint for the PC.

The game features a hexagonal grid made out of static meshes, it is generated when the game starts.
I’ve already got the coordination system, distance calculation, range and path finding working. (yay!)
At the moment the game is featuring just one kind of hexagon, but in the near future this is about to change.

I want to implement level designs into the game and of course at some point game must feature an online turn based system. The game must keep track of what factories/cities belong to what player, where all units are located etc… I have seen quite some real-time multiplayer networking tutorials, but nothing for turn based strategy games, especially focussing on mobile games. Also please note that I am working in blueprint.

What is the best solution to this problem? A database? Is it possible to transfer XML files?
Thanks in advance.

Yours sincerely,