When we have well-trained teams, facing real managers with poor tactics would be easier. Downside is new low-level teams would have little chances of winning against seasoned managers with ST finishing of 300%+ (Saying that, my level-1 team just beat such a team with 300%+ finishing by using 2DCs+DMC with no whites over 130% to mark him out of the match - There was practically not even tiny space between the 4 players).
Bots are easier for me when they won’t change around. Downside is engine often gives bot teams a 1-2 goal advantage in the first 20 mins regardless of initial team setup, Helen not ideal for counter attacking teams which rely on mainly close margin wins.