Cavalier one battles so-called rookies (9)

I believe the answer is:

neophytes

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'so-called rookies' is the definition.
The definition and answer can be both people as well as being plural nouns.
Maybe there's an association between them I don't understand?

'cavalier one battles' is the wordplay.
'cavalier' is an anagram indicator (a cavalier or careless spelling).
'battles' becomes 'phytes' (I can't justify this - if you can you should give a lot more credence to this answer).
'one' is an anagram of 'neo'.
'neo'+'phytes'='NEOPHYTES'

Can you help me to learn more?

(Other definitions for neophytes that I've seen before include "Newcomers" , "Novices" .)

I've seen this clue in the Sydney Morning Herald.

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