Different category labels for pie chart and legend

Try XY Chart Labeler free add-in from: http://www.appspro.com/Utilities/ChartLabeler.htm
use your column C as X axis for chart, but do not add data labels to slices standard way. in D2 write formula:

Formula:

=a2 & " " &TEXT(b2/b$15,"0%") 

or perhaps

Formula:

=a2 & char(10) & TEXT(b2/b$15,"0%") 

and copy down
Then use column D as labels for the slices.