Taking the words a bit out of context. She doesn't have the speed to get in close or toy with enemy but she has the eyes to react to his attacks.
So if someone like Boruto has the speed but not the reflexes but Sarada has the reflexes but not the speed then it cancels out pretty nicely. She can easily keep up the swordsmen ninja from earlier because she has the sharingan.
You said so yourself that this ninja was of much higher rank so her not having the speed to combat this particular enemy doesn't correlate to Shizuma or the other genin swordsmen.
So if someone like Boruto has the speed but not the reflexes but Sarada has the reflexes but not the speed then it cancels out pretty nicely. She can easily keep up the swordsmen ninja from earlier because she has the sharingan.
You said so yourself that this ninja was of much higher rank so her not having the speed to combat this particular enemy doesn't correlate to Shizuma or the other genin swordsmen.