I considered War Plan when it came out, but reviews mentioned its weak AI, that kept me away back then. Maybe it was chnaged meanwhile for the better?
Its been long time I played a classical hexfield cosim. The Operational Art of War III (strategic-operational level), and Flashpoint Campaigns (tactical level). Not Hexfield, but squares: Armoured Brigade. Recently, Flight Commander 2, also squares-based. Long Time ago: War in the East, the monster thing, you that one. That was overwhelming. Interesting, but not really enjoyable. I did not play the war to the end. It was more a warehouse management game.
That may be realistic, war is logistics before anything else, but it is not what keeps me endlessly interested in a game.
Even longer time ago, many other cosims.