includes.rb

module ServiceOne
  def helper_one
    puts "one"
  end
end

module ServiceTwo
  def helper_two
    puts "two"
  end
end

module Helpers
  include ServiceOne
  include ServiceTwo
end

class Test
  include Helpers

  def run
    helper_one
    helper_two
  end
end

Test.new.run

methods.rb

module ServiceOne
  def helper_one
    puts "one"
  end
  module_function :helper_one
end

module ServiceTwo
  def helper_two
    puts "two"
  end
  module_function :helper_two
end

class TestOne
  def run
    ServiceOne.helper_one
    ServiceTwo.helper_two
  end
end

class TestTwo
  include ServiceOne
  include ServiceTwo

  def run
    helper_one
    helper_two
  end
end

TestOne.new.run
TestTwo.new.run