Whose to say what the correct team spelling is? If the data is the same for similarly spelled team names, how about comparing the data rather than the team name:

my %good_data;
my @dups;

while (my $line = <DATA>) {

    my @fields = split /,/, $line, 2;
    my $team_info = $fields[1];

    if (! $good_data{$team_info} ){
        $good_data{$team_info} = $line;
    }
    else {
        push @dups, $line;
    }
}        

for (values %good_data) {
    print;
}       
print "*" x 20, "\n";  
      
for (@dups) {
    print;
}

__DATA__
Group One,Captain1,Phone Number,League Pos,etc. 
Group-One,Captain1,Phone Number,League Pos,etc. 
GroupOne,Captain1,Phone Number,League Pos,etc. 
Group Two,Captain2,Phone Number,League Pos,etc. 
Group Three,Captain3,Phone Number,League Pos,etc.




--output:--
Group Three,Captain3,Phone Number,League Pos,etc.
Group One,Captain1,Phone Number,League Pos,etc. 
Group Two,Captain2,Phone Number,League Pos,etc. 
********************
Group-One,Captain1,Phone Number,League Pos,etc. 
GroupOne,Captain1,Phone Number,League Pos,etc.
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