Í think you are right because Power was a less well-defined idea than War Assets. Both have a problem in how they're not really explained... I mean, what IS "1 War Asset"? How is this calculated and how much equals one dead Sovereign? Power is just... something. I can't decipher it. It's just an abstract score to symbolize how much power you have... really it's just a currency, they might as well have called it "Magic Money! Money that makes things happen!"
But yeah, the way they at least categorized war assets and made codex-like entries for all of them made it seem a little bit less arbitrary. I still had sort of an empty feeling after each non-plot mission because I didn't have a sense of what War Assets really was or how it worked. I kept going to the console expecting to find some kind of hidden interaction I had overlooked. "How do I use this thing??" I thought. Really, EMS was little more than a high-score and from the second I saw how it was turning all choices into points I already felt like the promise of "your choices matter" was just that: A highscore and little more. Thankfully multiple playthroughs proved me wrong to some extent but still. Was the EMS system even made so each war asset entry had a varible that could've worked like a squadmate in a suicide mission like in ME2? I didn't really feel like it did but I haven't datamined it.
Right, and this might be a little abstract to you, but what is power? Is power the ability to sleep with anyone? No, that comes with practice. Is power the ability to influence nations? No, the ability to tell the truth will matter more. So, what is power? The same goes with war assets. America, the mightiest nation, got its ass handed to us by a bunch of rice farmers in southeast Asia. Same war. Different kind.
EDIT : Damn, XCom 2 really has me thinking about guerrilla warfare. If you haven't been chased down by an alien spaceship, I wouldn't recommend it. I took out like 44/50 with 4 wounded, 4 killed, about 100 playthroughs of the same battle just to save one person who finally had achieved a nickname. It was brutal.