What does the cryptic crossword clue "Punches ain't less brutal (4,4)" mean?

The definition is "Punches". The wordplay uses an anagram. anagram of AIN'T + LESS = NAILSETS; definition: "Punches" The answer is NAILSETS.

Punches ain't less brutal (4,4)

Guardian Cryptic #29055 | 3 Down | 2023-04-27 flower