use strict;
use warnings;

my %usage;
my @sfull1ns = split /\n/, <<'FILE';
Server,Avg CPU,P95 CPU,Avg Mem Util,P95 Mem Util
WSOMQAVPRA05,93.75,95.87,66.67,68.13
wsomdavpra03,90.39,94,65.77,68.51
wsomddvfxa01,39.22,92.19,82.59,88.25
wsomddvfxa01,35.45,89.23,79.89,83.24
FILE
my @sfull2ns = split /\n/, <<FILE;
Server,Avg CPU,P95 CPU,Avg Mem Util,P95 Mem Util
WSOMQAVPRA05,34.78,100,55.1,67.6
wsomdavpra03,69.04,98.55,84.07,89.73
wsomddvfxa01,92.44,97.54,67.72,71.69
wsompapgtw05,48.77,96.9,92.1,93.55
FILE
my @sfull3ns = split /\n/, <<FILE;
Server,Avg CPU,P95 CPU,Avg Mem Util,P95 Mem Util
WSOMQAVPRA05,93.13,98.11,68.95,73.47
wsomdavpra03,68.85,97.56,76.35,98.23
wsomddvfxa01,46.97,96.29,88.23,94.02
wsompapgtw05,30.66,93.74,39.89,71.35
FILE

for my $fileData (['File A', \@sfull1ns], ['File B', \@sfull2ns], ['File C', \@sfull3ns],) {
    my ($filename, $data) = @$fileData;
    
    shift @$data;
    
    for my $line (@$data) {
        chomp($line);

        my ( $server, @data ) = ( split( ",", $line ) );

        $usage{$server}{$filename}{value} ||= $data[0];
    }
}

for my $file ('File A', 'File B', 'File C') {
    $usage{$_}{$file}{value} ||= 0 for keys %usage;
}

for my $server (sort keys %usage) {
    print "$server,",
        join (',', map {$usage{$server}{$_}{value}} sort keys %{$usage{$server}}),
        "\n";
}

##</code><code>##

WSOMQAVPRA05,93.75,34.78,93.13
wsomdavpra03,90.39,69.04,68.85
wsomddvfxa01,39.22,92.44,46.97
wsompapgtw05,0,48.77,30.66