That group in charge sucks at relating to subjects (8)
I believe the answer is:
thematic
'relating to subjects' is the definition.
(I know this)
'that group in charge sucks at' is the wordplay.
I cannot really understand how this works, but
'at' is present in the answer.
'in charge' could be 'ic' (abbreviation for 'in charge') and 'ic' is present in the answer.
The remaining letters 'them' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for thematic that I've seen before include "Topical" , "Relating to a particular topic" , "on one particular topic" , "Related to a particular subject" , "Relating to a motif" .)