If you are able to ... then change your data! :)

my %hash = (
    EX     => { sort => 30, data => 'ArraySite' },
    AM     => { sort => 40, data => 'IOPort' },
    PLE    => { sort => 20, data => 'AddressGroup' },
    Number => { sort => 1,  data => '11' },
);

for my $key (sort { $hash{$a}->{sort} <=> $hash{$b}->{sort} } keys %ha
+sh) {

    print $key, " => ", $hash{$key}->{data}, "\n";
}
[download]

What happens when 'Number' has to be renamed, or another key is added whose length is longer than 'Number?' I would first try to make the data work for me rather than the other way around, if possible.

L-LL-L--L-LL-L--L-LL-L--
-R--R-RR-R--R-RR-R--R-RR
B--B--B--B--B--B--B--B--
H---H---H---H---H---H---
(the triplet paradiddle with high-hat)