The quote is as such:
 quod Cicerō optimē videt ac testātur frequenter sē quod numerōsum sit quaerere, ut magis nōn ἀπάλαιστοι. quod esset īnscītum atque agreste, quam ἔνρυθμον, quod poēticum est, esse compositiōnem velit; sīcut etiam quōs palaestrītās esse nōlumus, tamen esse nōlumus eōs quī dīcuntur ἀπάλαιστοι.
I am interested in the latter part of the phrase, which I have translated to:
Just as we certainly do not wish some to be gymnasts, we still do not wish them to be those that are said [to be] ignorant of gymnastics.
The phrase ‘ignorant of gymnastics’ is my version of Butler’s translation. The problem I have, though, is that the dictionary entries I have access to explain ἀπάλαιστοι as such:
ἀπάλαιστος [πα^], ον,
A.not to be thrown in wrestling, unconquerable, Pi.N. 4.94.
1.unbeatable in wrestling, met. “οἷον αἰνέων κε Μελησίαν ἔριδα στρέφοι, ῥήματα πλέκων, ἀπάλαιστος ἐν λόγῳ ἕλκειν” not to be thrown in his speech, Bowra N. 4.94
This seems to be in direct contradiction to the interpretation by Butler. What is the explanation for this interpretation of the word (other than that it wouldn’t make sense the other way)? May it be that some Greek words had taken on their own meaning in the Roman discourse, and that Quintilian is using this word in that sense. I doubt this to be true, though; it doesn’t seem likely, given the high status of Greek amongst the Roman élite.