Don't take any extra personnel to north Wales region (7)
I believe the answer is:
rhondda
'wales region' is the definition.
The definition suggests a singular noun which matches the answer.
'don't take any extra personnel to north' is the wordplay.
I cannot quite see how this works, but
'take' could be 'r' (abbreviation for 'recipe', Latin for 'take') and 'r' is found within the answer.
'north' could be 'n' (abbreviation) and 'n' is found within the answer.
'extra' could be 'odd' (I've seen this in another clue) and 'odd' is located in the leftover letters.
The remaining letters 'ha' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for rhondda that I've seen before include "Welsh valley known for mining" , "Welsh valley, mined once" , "Welsh ex-mining valley" , "Former coal-mining centre in South Wales" , "Welsh constituency" .)