Why dont you slurp each file into any array then use a for loop to print 1 record from each file at a time
quick bit of code
use strict;
my @file1 = ("1 G","2 F","4 H","8 T");
my @file2 = ("5 Y","6 R","7 E","8 I");
my @file3 = ("2 H","4 T","3 G","8 R");
my $largest_array = scalar @file1;
$largest_array = scalar @file2 if(scalar @file2 > $largest_array);
$largest_array = scalar @file3 if(scalar @file3 > $largest_array);
my @array =(\@file1,\@file2,\@file3);
for (my $ctr =0;$ctr <= $largest_array;$ctr++){
print $array[0][$ctr] if($ctr <= scalar @{$array[0]});
print $array[1][$ctr] if($ctr <= scalar @{$array[1]});
print $array[2][$ctr] if($ctr <= scalar @{$array[2]});
print "\n";
}
print "\n\nComplete";