Powerful and not-so-clever group (8)
I believe the answer is:
thickset
'powerful' is the definition.
Both the answer and definition are adjectives. Maybe there's a link between them I don't understand?
'not-so-clever group' is the wordplay.
'not-so-clever' becomes 'thick' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'group' becomes 'set' (both can mean a collection).
'thick'+'set'='THICKSET'
'and' acts as a link.
Can you help me to learn more?
(Other definitions for thickset that I've seen before include "Heavily built" , "squat" , "Compact" , "Beefy" , "sturdy" .)