A Constitutional Monarchy is a government sharing the ideals of a monarchy with a key difference, a law or constitution preventing absolute power. This reduces the Monarch's power effectively and in some cases makes the monarch nothing but a figurehead.
There is no corruption, due to the fact that the monarch is acting not only on their own opinion, but on the constitution's will.
If applied to a clan, in a large clan government positions would be desired, due to the fact that the monarch couldn't do it all them selfs effectively.
There's no bureaucracy to getting things done, as the monarch would do things under their own opinion, limited by the constitution.
If applied to a clan, in a small clan government positions are almost undesirable due to the monarch taking control of all that the constitution does not prevent.
Members don't have the ability to vote for leaders, unless the constitution calls for an elected monarch when one manarch is removed or steps down.