Forty crews too disorganised (3,5)

I believe the answer is:

two score

'forty' is the definition.
(a score means twenty)

'crews too disorganised' is the wordplay.
'disorganised' indicates anagramming the letters.
'crews'+'too'='crewstoo'
'crewstoo' is an anagram of 'TWO SCORE'.

I've seen this clue in The Independent.

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