I've spent the past hour or so looking through the forums looking at several suggestions for ground combat and noticed a few trends that cause them to be denounced by the greater community and even the Wiz himself. Almost every suggestion seems to involve some sort of minigame or player interaction that takes up your micro time and bogs down multiplayer. So I felt the need to try my hand at keeping it automated but making it more complex then spaming assault armies. I hope I've struck a good balance.
The fact that you don't want to add micro makes this immediately better than most suggestions aimed at "improving" ground combat (I would say, though, that having more options in how to design your planetary defense or invasion force
is micro too. Micro doesn't have to just be referring to direct control of troops - any suggestion that fleshes out some mechanic to involve more interesting choices necessarily increases the amount of micro the player needs to do to manage it). But your suggestion falls victim to exactly the same issue all but one such suggestion I've seen does: it addresses the wrong problem.
The problem is not really that most suggestions to flesh out ground combat are boring, micro-heavy slogs. The problem is that ground combat has (unless you're abusing shoddy warfare AI behavior) essentially no bearing on the outcome of the war, and therefore ground combat is
intrinsically boring.
Does your suggestion address the fact that in order to launch invasions, you almost certainly have to have naval superiority in space? Does it address the fact that once you have naval superiority there is nothing that stops you from
keeping naval superiority as long as you play intelligently? Does it address the fact that once you have naval superiority, it is literally just a matter of time to conquer any world, no matter how well-defended, and that therefore invasions are just an unnecessary waste of time for the outcome of the overall war?
No?
Then you haven't really solved the problem.
I'd be fine with more fleshed-out ground combat in the style you have here, but only if the implementation didn't take away from dev time on more important core mechanics of the game. And I wouldn't advocate for its inclusion, and I honestly wouldn't see any kind of strategic use from playing around with it - why defend on the ground when having a powerful navy is far more important? It would just be a mildly interesting thing for a bit, and then would get boring once it was clear that it once again didn't matter to the course of the war.
The real way to "fix" ground combat and planetary defenses, to make it interesting and engaging, is to come up with a way for planetary defenses to actually impact the course of the war. Not by making it take longer to invade a world, because that doesn't change anything. Rather, planetary defense should be improved by making it harder for your opponent to maintain the naval superiority they need to be able to launch invasions in the first place.