Code:
class Window_ActorCommand < Window_Command
  def add_skill_commands
    @actor.added_skill_types.sort.each do |stype_id|
      name = $data_system.skill_types[stype_id]
      add_command(name, :skill, (@actor.skills.size > 0), stype_id)
    end
  end
end
Nicht getestet, sollte aber funktionieren.