If it is just a matter of UPPERCASE v. lowercase, you can force both strings to lowercase and then do the comparison.

Did you already have a look at Array::Compare? Incidentally, the simple compare method also uses "my" concatenation trick.

Having had a quick peek at String::Approx I think it can be used with this concatenation trick: rather than test on eq you test on adist or adistr and see if both strings are sufficiently equal to be accepted as such or must be checked further.

String::Similarity might also be a good candidate: it seems simpler than String::Approx.

CountZero

"If you have four groups working on a compiler, you'll get a 4-pass compiler." - Conway's Law