This is my code. Less var changes, more eficient (?)...

sub split_array_in_two {
 my $len = int($#_/2); 
  return unless ( @_ );
 return [ @x[0..$len] ], [ @x[$len+1..$#x] ]; 
}
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scalar(@_) is numbered from 1 to elements... and
$#_ is numbered from 0 to limit.

Your code isnīt long... is readable and suficient.