Playing easy is boring, playing medium forces you too much. I think medium should be a little easier.
The ‘hardest’ AI crumbles instantly if pressured 
Tries to shank your raiders with its vils and just starts getting confused, taking resources without a nearby collection building, etc.
Guys… there’s never gonna be a setting thats exactly right for you. People ar ecomplaining easy is too hard, easy is too easy, moderateo is too hard easy too easy. Comeon. Just accept sometimes in life you meet challenges that you don’t instantly overcome.
I had the same problem in AOE-2, medium was hard. So i am dissapointed that AOE-4 has the same problem.
edit: I only could defeat medium AI as France in the map Black forest. Enemy was chinese. I attacked in feudal with rams.