All it takes is a couple of regexes :)

#!/usr/bin/perl

# https://perlmonks.org/?node_id=1224689

use strict;
use warnings;

my $newdata = <<END;
Puma
77777 33333 44444 55555
Adidas
99999 88888 55555 77777
22222 11111 33333 44444
Brooks
11111 22222 33333 44444
33333 44444 55555 66666
END

my $olddata = <<END;
Puma
77777 33333 44444 55555
Adidas
11111 11111 33333 44444
99999 88888 55555 77777
Brooks
11111 22222 33333 44444
33333 44444 55555 66666
END

local $_ = $newdata . $olddata;
my $label = "\t\t\t  New\t\t\t\t  Old\n\t\t" .
  "  x1    y1    x2    y2\t\t  x1    y1    x2    y2";

print "Matching\n$label\n";

1 while s/^
  ([a-z]+)\n \K
  ( (?:\d\V*\n)*?)
  (\d\V*)\n
  ( .* ^\1\n (?:\d\V*\n)*? )
  \3\n
  / print "$1\t\t$3\t\t$3\n"; "$2$4" /gmixes;

print "\n\nNot matching\n$label\n";

1 while s/^
  ([a-z]+)\n \K
  (\d\V*)\n
  ( .* ^\1\n)
  (\d\V*)\n
  / print "$1\t\t$2\t\t$4\n"; $3 /gmixes;
[download]

Outputs :

Matching
                          New                             Old
                  x1    y1    x2    y2            x1    y1    x2    y2
Puma            77777 33333 44444 55555         77777 33333 44444 5555
+5
Adidas          99999 88888 55555 77777         99999 88888 55555 7777
+7
Brooks          11111 22222 33333 44444         11111 22222 33333 4444
+4
Brooks          33333 44444 55555 66666         33333 44444 55555 6666
+6


Not matching
                          New                             Old
                  x1    y1    x2    y2            x1    y1    x2    y2
Adidas          22222 11111 33333 44444         11111 11111 33333 4444
+4
[download]