my $find = "find /path -type f -print0 | xargs -0 md5"
for my $host ( @hostlist ) {
    open O ">$host.md5list" or die "$host.md5list: $!";
    print O `ssh $host '$find'`;
    close O;
}

# compare lists here, if you like, or use a separate script/tool to do that