Asalaam Alaikum.
It is well known that the Prophet (pbuh&hf) prophecied about 12 Leaders after him.
The twelve Leaders of the Shias are supported by the Ahadith of the Prophet of Allah. This is proven by the Shia Hadith collections. Kifayat al-Athar is a famous collection which has gathered many reports, in that regard, from different routes.
Do the Sunnis have anything to support their 12 Leaders, or are they content with guess work only?
I believe that the shias have an upper hand in this matter.
Rude boys, you can stay out of the discussion. Sunni intellectuals, do contribute to the topic with valid responses.
Regarding the Shi’a belief, then it’s enough to see what an esteemed Shia scholar had to say which exposes the confusion early Shias had.
Shia scholar of Hadith Muhammad Baqir al-Behbudi writes in "Ma`rifat al-Hadith" pg.172:
على انك عرفت في بحث الشذوذ عن نظام الامامة ان الأحاديث المروية في النصوص على الأئمة جملة من خبر اللوح وغيره كلها مصنوعة في عهد الغيبة والحيرة وقبلها بقليل فلو كانت هذه النصوص المتوافرة موجوده عند الشيعة اللإمامية لما اختلفوا في معرفة الأئمة هذا الاختلاف الفاضح ولما وقعت الحيرة لأساطين المذهب واركان الحديث سنوات عديدة وكانوا في غنى ان يتسرعوا في تأليف الكتب في اثبات الغيبة وكشف الحيرة عن قلوب الامة بهذه الكثرة
[And you (reader) now know after the research on "al-Shudhudh `an Nizam al-Imamah" that the narrations about the general identity of the Imams such as the narration of the Tablet and others, are all fabricated during the time of al-Ghaybah and al-Hayrah and some short time before it. For if these narrations were available with the Imami Shia, they would not have disagreed so openly and greatly about the identity of the Imams, nor would the biggest personalities and narrators of Hadith have faced much confusion for long years, nor would they have needed to quickly write books proving the Ghaybah to unveil the confusion from the hearts of the nation in such great numbers.]
As for the Sunni view then, as per Sunnis the other authentic traditions of Prophet(saws) and the understanding of Sahaba refutes the Shi’a belief. For example, the hadeeth of Caliphate on Manhaj Nabuwwah being for 30 years. And how Safeenah(ra) understood it, which is actually a pro Ali(ra) narration. Or the hadeeth of Ibn Umar(ra) wherein he described who the Twelve Caliphs included Abubakr(ra) and Umar(ra).
This certain info and it refutes the Shi’a belief, now when Shias realize then they want to divert the focus from the real refutation to their not much related questions. Like who are the rest Caliphs. But they fail to realize that even if Sunnis disagree over the identity of later Caliphs and are uncertain, yet what is certain and established among Sunnis destroys the Shi’a belief. That is, the initial ones are those who aren’t considered as Shi’a Imams, and this is sufficient to reject the Shi’a belief.