Disorderly crowd and some player (5,4)

I believe the answer is:

scrum half

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'player' is the definition.
Both the answer and definition are singular nouns.
Perhaps there's a link between them I don't understand?

'disorderly crowd and some' is the wordplay.
'disorderly crowd' becomes 'scrum' (I've seen this before).
'and' says to put letters next to each other.
'some' becomes 'half' (I can't justify this - if you can you should give a lot more credence to this answer).
'scrum'+'half'='SCRUM-HALF'

Can you help me to learn more?

(Another definition for scrum half that I've seen is " Rugby player -- March's flu (anag)".)

I've seen this clue in The Daily Express.

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