Split peas poorly regarded (9)

I believe the answer is:

separated

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'split' is the definition.
(I've seen this before)

'peas poorly regarded' is the wordplay.
'poorly' indicates an anagram.
'regarded' becomes 'rated' (I can't justify this - if you can you should believe this answer much more).
'peas' with letters rearranged gives 'sepa'.
'sepa'+'rated'='SEPARATED'

Can you help me to learn more?

(Other definitions for separated that I've seen before include "Split" , "Pulled apart" , "Distinguished -- divided" , "in different cages?" , "No longer connected or joined" .)

I've seen this clue in The Daily Express.

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