What does 'manage that much' mean here? And, please, explain why 'much' is used in this case and its meaning.
Then the door to the cafeteria/gym opened, and a Mr. Jenkins came out. Which Mr. Jenkins? There was no telling them apart. Meg looked to the cherubim, but he had de-materialized again, leaving only a shimmer to show where he was.
Mr. Jenkins came to her. She checked his shoulders. There was the dandruff. She went closer: smelled: yes, he had the Mr. Jenkins smell of old hair cream and what she always thought of as rancid deodorant. But all three of the Mr. Jenkinses could manage that much, she was sure. It was not going to be that easy.
From A Wind in the Door by Madeleine L'Engle.