count with scoped :from option

I tryed the following:

class Foo < ActiveRecord::Base
  named_scope :top10, :from => "(SELECT * FROM foos ORDER BY foos.rank DESC LIMIT 10) AS foos" do
    def count(*args)
      options = args.extract_options!
      options[:from] ||= proxy_options[:from]
      args << options
      super(*args)
    end
  end
end

This works fine with count, but doesn't make sense for (will-)paginate.

Foo.count => 20 Foo.top10.count => 10 Foo.top10.paginate(:page => 1, :per_page => 5).total_entries => 20

Is there any other solution to solve this problem?