I just noticed the following in Piwik 2.7.0:
You can see that Realplayer is above Director although it has a lower percentage and this is sorted by the percentage of the visitors. I assume that the sort is lexical after the format is applied. The numbers should be sorted before the format is applied. A quick fix would be to use leading zeros, but that is rather ugly.
Thanks for the report!
This bug can be reproduced in German language. Related to #4114
I can reproduce this issue also with English language