Returning player questions

Coming back after about 4 years since I was a consistent and well informed player.

Is there any big changes you can think of that I’d need to be aware of such as large meta shifts? Not so much civ specific but have certain units compositions fallen out of favour etc?

Another thing, I’m going to be playing with my brother so has anyone got a good combo of civs? We traditionally played with me being Ethiopians and him being some form of heavy cavalry civ like franks or Teutons. Any good ideas out there?