Economy is hard to plausibly estimate because there can be things just outside LOS that are totally wrong: like huge reclaim fields, millions of workers each producing 0.2 income, or just a singu field attached to mexes you cannot see.
However, there's ground control, which is in fact easy to estimate; and in a zero-sum game like ZK, you can just estimate HostileTerritory = 1 - MyTerritory.
Maybe i should make a "Ground Control Counter" widget akin to the casualties counter that would display scary numbers like "Ground control: 0%" from start to make you expand faster.