Assuming the ground stations are in a hexagonal grid, the generator station is at the center of the center hexagon, and the transmission method is only allowed to go along the edges of the hexagon. So if you imagine the vertexes of the hexagons as nodes in the power transmission network, then you could perhaps connect a single generator station to 6, 12, 24, 36 systems if you allow for 0, 1, 2, 3 relay stations let’s call them for now. Assuming 0.9 efficiency of the relay/transmission method then the power from the outermost system delivered to the generator station would be reduced to 0.9^4 = 0.6561 for 36 connected systems or 0.9^3=0.729 for 24 systems. Actual efficiency could be higher.
There are of course other possible geometries, like a number of lines coming from the generator station that at specific points along their length have multiple other lines branching from them. Perhaps lines coming from nodes further away from the generator station don’t need to connect to all the nodes along the path, instead just running parallel to the lines coming from nodes closer to the generator station.
The possibility of only needing one generator station for 24 systems for example is interesting enough to warrant further exploration I think. You could also explore replacing the generator in the station with something else, say 6 smaller generators, or a single smaller generator as a pilot study.
Simpler would be to house all the drums in the generator station also and connect them to the generators, with the tether from each system going all the way to the generator station, the other nodes just redirecting the tether. Something like this was also something Zhonglu High Altitude Wind Power Technology - 中路高空风力发电技术 did or planned to do, 4 systems for one generator station.