# First, sort @arr1.
@arr1 = sort {
   my ($c) = $a =~ /:::(\d+)$/;
   my ($d) = $b =~ /:::(\d+)$/;
   +$c <=> +$d
} @arr1;

# Then recreate @arr2.
@arr2 = map { s/^.*:::(\d+)$/$1/ } @arr1;