Question about Campaign difficulty AOE 2 DE

So I've recently jumped into AOE 2 DE's campaigns and I'm getting thrashed even on standard. I'm no rts God but I'm not a novice either as I've played a bunch and usually do fairly well especially on easy.

I've tried to do a little bit of research and it seems like DE's AI is better. I blew through Wallace's campaign like it was nothing but had a slog going through El Cid and now am struggling with Genghis Khan. Am I missing anything or any tips? Both would be helpful.