All the grid cells locations are stored in an array. So if you want something that’s completely random, yes it’s simply a matter of getting random elements from said array and placing an actor or mesh component at that location. Here is an example scenario where we have 40 blocks randomly spawned on a 20x20 grid across a 400x400 sq units area:
And here’s another with 100 blocks:
From there you can take it and even randomize the buildings as well from a pool of mesh components or actors.