Like twins in citadel roaming (9)

I believe the answer is:

identical

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'like twins' is the definition.
'identical' can be an answer for 'like' (I've seen this before). I am not sure about the 'twins' bit.

'in citadel roaming' is the wordplay.
'roaming' is an anagram indicator.
'in'+'citadel'='incitadel'
'incitadel' is an anagram of 'IDENTICAL'.

Can you help me to learn more?

(Other definitions for identical that I've seen before include "Indistinguishable" , "showing no change" , "Like two peas in a pod" , "Selfsame" , "lacking distinction" .)

I've seen this clue in The Sun.

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