From the previous Follower card PK, Spinach had already figured it out.
The opponent was a new card player.
The Follower cards he played kept changing, none were very strong, and his technique was quite rusty.
Furthermore, the progress of "Way of Balance" only being at "Second Pass Nine" confirmed Spinach's guess.
Anyone who hadn't reached the "Third Gate" couldn't be considered as one who truly crossed the threshold as a card player.
So Spinach thought that the reason Wembley Brown wanted him to compete with himself was just for making a favor.
They were all friends; a 1:1 score would look better.
Just consider it as swapping "Way of the Wind" for a "Way of Balance."
However, he must think highly of this new coach, so he took the opportunity to send a favor to himself while letting the other party practice a bit.
Each card player has their own style and routine, and even though card players with the same style have some subtle differences in certain aspects.