Excessively focussed on one area, rewriting adverse policies (15)

I believe the answer is:

overspecialised

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'excessively focussed on one area rewriting adverse policies' is the definition.
I can't judge whether this definition defines the answer.

'rewriting adverse policies' is the wordplay.
'rewriting' indicates anagramming the letters.
'adverse'+'policies'='adversepolicies'
'adversepolicies' is an anagram of 'OVERSPECIALISED'.

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(Another definition for overspecialised that I've seen is " No jack-of-all-trades".)

I've seen this clue in The Guardian.

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