I struggled here for some time before beating it with Mordor, but in between I lost with Gondor, Rohan, Imladris, Lothlorien and Dwarves. 

The key was an unrelenting multi-source spam and a sprinkling in of mountain trolls and catapults. I only made 2300 units though, so it wasn’t a long lasting spam. Angmar just couldn’t deal with my numbers. I guess I got kind of a choice matchup to get the win, but I still had to capture the map to get mine. And that’s exactly what those orcs did, they swarmed over the map and purged enemy structures and units alike. I was able to hold ground and gain new ground effectively once I had an outpost in the north. Then the multi-sourcing began. Soon I had troops amassing in the east and west narrows. I knew then I had it. 

Catapults finished the deal, but orcs were there to help. Orcs were fucking everywhere, all the time. 

But now I’m stuck on a whole new map. Puzzled as to how I’m going to get past it. Haven’t tried everyone yet, but lost with most by now. So I’ll keep you posted.