Is there no direct logical correlation between 'At best, experience with different combinations of waist sizes and leg lengths for a given design allows a scheduler to aggregate the units to be made into groups of large and small sizes, which means marker-makers can achieve efficiencies near 90 percent for casual pants.' and 'Marker-makers can only achieve efficiencies of 80 percent if they do not aggregate the units to be made into groups of large and small sizes.', indicating neutrality?
At best, experience with different combinations of waist sizes and leg lengths for a given design allows a scheduler to aggregate the units to be made into groups of large and small sizes, which means marker-makers can achieve efficiencies near 90 percent for casual pants.###Marker-makers can only achieve efficiencies of 80 percent if they do not aggregate the units to be made into groups of large and small sizes.