Your code works for $foo, but unfortunately not for the more complex structure

Well, as I said, easily fixed with an if. More representative sample input data gets you better answers ;-) The following should work on AoH and HoH, but not yet on AoA, and the root must be a hash. Extending this further is left as an exercise to the reader...

sub rekey {
    my $h = shift;
    KEY: for my $k (keys %$h) {
        if (ref $$h{$k} eq 'ARRAY') {
            rekey($_) for @{$$h{$k}};
            my %n;
            for my $e (@{$$h{$k}}) {
                next KEY unless exists $$e{name};
                die "duplicate key '$$e{name}'"
                    if exists $n{$$e{name}};
                $n{$$e{name}} = $e;
            }
            $$h{$k} = \%n;
        }
        elsif (ref $$h{$k} eq 'HASH')
            { rekey($$h{$k}) }
    }
}
rekey( $foo );
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Update: I realized based on the sample data that you posted here that not all of your hashes in the AoHs have "name" keys. So I modified the above to skip transforming such AoHs with next KEY unless exists $$e{name};. Other approaches are of course possible too, if you can identify a useful key. Update 2: I applied that change a little too hastily, it wasn't correct as it wasn't recursing into the full data structure anymore. Fixed.