How did she struggle? And they've had him fight Superman numerous times so its not like Diana is being singled out as some sort of weakling.
Majority of Dianas villains shouldnt be a threat to her with how much some want her to go up against other godly creatures. Dr. Psycho, Dr. Poison, Blue Snowman, Nazis, OG Cheetah, should be beaten within seconds. She should only go up against Gods, Kryptonians. At the end of the day, some of it is just pure fun and as long she comes out the victor, I am ok with it. If she is beaten then it needs to be a good reason. Her fight with Deathstroke was fun to me so I dont got a problem with it.