sort can take a compare function. Extract the digits and compare them.

@array =
   sort {
      my ($digits_from_a) = $a =~ /(\d+)\z/;
      my ($digits_from_b) = $b =~ /(\d+)\z/;
      $digits_from_b <=> $digits_from_a
   }
   @array;
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Same, but a bit more terse:

@a = sort { ($b =~ /(\d+)\z/)[0] <=> ($a =~ /(\d+)\z/)[0] } @a;
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The aforementioned Schwartzian Transform is an attempt to optimise this.