Another solution could be, that not all of the resources are mineable at once. So, when you scan a tile, you get an idea of how much ore there is. But it would spawn over time in smaller veins. That way people would not be able to scan and strip mine a tile, they would have to claim it and keep mining it for a longer time. Would also make territory control more important. Currently people just mine out the higher tier ores, and then abandon the territory.