You mentioned Orbital Drop being overpowered (which it is, as it works currently, though it can be vaguely compensated for); will you be reducing it to a +1 bonus at some point in the future?
And how does combat aboard ships/Board work/accomplish?
And, uh...I feel like right now it's just a game of numbers, since it's so easy to move troops around in vaguely similar regions, and outnumbering someone more than is necessary to win does absolutely nothing. (20 Regular Regiments attacking 10 Regular Regiments will take the same casualties, in absolute terms, as 50 Regular Regiments attacking 10 Regular Regiments. Since all battles are effectively 1v1, for defending, as long as you still have manpower, having fortresses larger than Small at most is inefficient(although a single Indomitable Fortess is still useful)) While I don't know if the way it was before actually would have made a difference, it doesn't matter at the moment whether you control every inch of a region's borders and are sending troops from every direction at once, or are trying to force that same massive army through a tiny (presumably fortified) pass.
Logistics chains is abstracted away to nothing, and space battles are also numbers, except a bit more random/tactical-y because of the battle actions.
I don't know if that's what you were going for (space seems fine, at least, because while it's fairly straight numbers at base, actions make it interesting), but ground battles seem like they could use some tactics, though I know that could get excessively complicated. Not trying to criticize, mind you, I know it can come across like that. Just trying to point it out; running this seems like it takes a lot of time, and the flavor you use/add to the battles is pretty good in itself.
...What do you mean, I'm only bringing it up because the Miner's Collective seems terrifyingly powerful if it's entirely numbers? Don't be ridiculous.