>>718672215 (OP)
A combination of C&C 3/KW, Sins of the Solar Empire/Homeworld, and Endless Space 2.
For most part game plays like ES2, except that when you do space battles, you do them SotSE-like, and when you do ground invasions/defence, you pretty much play C&C. You can ofcourse use auto-resolve and battlecards too.
Also, just like ship module designs in ES2, you can do that to planetary defence and structures (orbital fire bases/stations, fighters/bombers/etc, ground units (vehicles, troops, mechs, etc), bunkers and fortifications, naval units (especially if there are large bodies of water/oceans), transports, trade and freight ships.
Also, you can capture enemy units and reverse-engineer their tech (that is modules and gain boost to research of related technologies), sell or retrofit those units, use those units as spies/decoys. Same with planetary/system upgrades and technologies.
For example. Your enemy discovered ultradense titanium slugs (mass drivers). You have not. If you capture his unit(s) that have this module, you can research this module and it will become available to you, and also get some progress on tech/research tree, or outright unlock this research. It will take some science resource, but you get module and possibly tech for less science than it would take you to research it normally. Same with planetary/system upgrades. You capture a system that has Simulation Camps built. Normally, you cannot research this upgrade, you can only find it from anomalies/curiosities. So you can spend some industry and science to research it and thus gain an option to build it, and gain some progress to a relevant technology in the military sector.
Sorry for an old image, i just realised i have not made any shots from recent times. So here you go.