You might also find the following useful:

use warnings;
use strict;
use Data::Dumper;

my %h1 = ( "one" => 1, "two" => 2, "three" => 3, );
my %h2 = ( "four" => 4, "five" => 5, "six" => 6, "one" => 11111, );

my $grand_hash_ref = {};

foreach my $hash_ref ( \( %h1, %h2 ) ) {
    while ( my ( $key, $value ) = each %{$hash_ref} ) {
        push @{ $grand_hash_ref->{$key} }, $value;
    }
}

print Dumper $grand_hash_ref;
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