Shias what do you say of this hadith regarding the ottomans?

they were after the 12 Imams right? so their is no need for us to disagree on that? if they r no more 12 imams then we have to choose other. we just think it should be the Prophets decendent if they r no more then we will accept others as Khalifah. the ottomans did a good job. too bad they fell apart.