I dont want to answer for GoalGerd, but after downloading this myself, it's more a case, that it changes, players dribble style in edit mode, so that different players run differently to other players. Without the option file, nearly every player runs using the dribble style "1", the default, however with this option file, GoalGerd has changed player dribble styles so that when playing you see a variety of different dribble or run styles, to make the running more varied and less robotic.
You can also edit the way the AI plays the game by changing teams "mentality". Therefore you can effectively make the AI more attacking, so more goals are produced per game, as result changing the gameplay.
(Correct me if I am wrong anyone
)
Hope this answers your question.