There is an error in the Shape Sleeve instructions for the small size on page 125 in Custom Knits 2 where the pattern appears. The last statement of the 1st paragraph of Shape Sleeve says:

Work even until piece measures 3 3/4 (4 3/4, 4 1/4, 4 1/4, 5, 5, 5)” from underarm.

The size small should read 3 3/4”.