Inheriting from Class::Accessor gives you the mk_accessors method:

package Big::Thing;
use strict;
use base qw(Class::Accessor Small::Thing Needful::Things);

__PACKAGE__->mk_accessors(qw(field1 field2 field3));

sub new {
  ...
  return $package->SUPER::new({ %args });
};
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Class::Accessor has the shortcoming that its constructor wants to be passed a hash reference. So you need to either override the default constructor or live with that.