Ungentlemanly type, even worse with a different leader (7)
I believe the answer is:
dastard
'leader' is the definition.
The definition and answer can be both people as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for dastard that I've seen before include "Cowardly fellow" , "despicable fellow!" , "contemptible scaredy-cat" , "Coward" .)