Here are the various forms of the Ahadith:
Jaabir ibn Samarah related that he heard the Messenger of Allah say, “Indeed before the Hour there are liars.” Jaabir said, “So beware of them.” (Muslim)
This hadith doesn’t mention Dajjaal’s, but Liars.
Jaabir also related that he heard the Messenger of Allah say, “Indeed before the Hour there are liars; among them is the one of Al-Yamaamah, the one of San’aa Al-‘Absee, and the one of Himyar. Also among them is Ad-Dajjaal, he creates the most Fitnah (strife and tribulations).” Jaabir said, “Some of my companions say that they are almost thirty men.” (Ahmad)
Here we see the Prophet (pbuh) not mentioning in ‘My Ummah’ because the first three Dajjaal’s identified by the prophet (pbuh) did not accept his prophet hood they challenged it outright.
Abu Hurairah related that the Messenger of Allah said, “The Hour will not come to pass until thirty Dajjaal Liars come out; each one of them lies upon Allah and upon His Messenger” (Abu Daawood)
Here he mentioned 30 Dajjaal’s, and says they will lie upon Allah and his messenger but doesn’t mention them claiming to be prophets.
Abu Hurairah related that the Messenger of Allah-, said, “There will be Dajjaal Liars in my nation; they will come to you with novel speech, which neither you nor your fathers had previously heard. Beware, and let your fathers beware – do not allow them to deceive you.” (Ahmad)
Here He (pbuh) specifies the Dajjaal’s are in his nation and they will come with something new but He (pbuh) didn’t say they will claim Prophet hood.
Abu Hurairah related that the Prophet said, “The Hour will not arrive until almost thirty Dajjaal Liars are sent; each one of them will claim that he is the Messenger of Allah.” (Muslim)
This is the most known form of this Hadith, there will be almost 30 Dajjaal’s claiming to be prophets.
Ibn ‘Umar said, ‘By Allah, during the period of the Messenger of Allah, we were neither doubters nor fornicators.’ He then said, ‘By Allah, I heard the Messenger of Allah say: Al-Maseeh Ad-Dajjaal (Anti Christ) and thirty liars or more will indeed come before the Day of Judgment.'” (Ahmad)
Here Ibn Umar mentions they will be 30 or more Dajjaal’s by the day of judgment.
Ibn ‘Umar related that he heard the Messenger of Allah say, “In my nation, there are indeed Nayifan (a number anywhere between 3, 9 and 70); each one of them is a caller to the Hellfire. If I wish, I can inform you of their names and tribes.” (Related by Al-Haafiz Abu Yatlaa – Ibn Kathir in the Book of The End)
These are smaller Dajjaal’s and they will be up to 70 or more in his Ummah.
Anas related that the Messenger of Allah said, “Before Ad-Dajjaal there will be Nayifan (smaller) Dajjaals.” (Ibn Kathir in the Book of The End)
Up to 70 Nayifan but it doesn’t specify in his Ummah.
Once the Prophet of Allah said, while delivering a ceremonial speech at an occasion of a solar eclipse, as Samura ibn Jundub reported: “…Verily by God, the Last Hour will not come until 30 liars of prophecy will appear and the final one will be the One-eyed False Messiah.” (Imam Ahmad).
Huthaifa narrated, that the Prophet said: “In my Ummah (community/nation), there are 27 dajjaal liars, including 4 women. I am the last Prophet and none will come after me.” (Related by Imam Ahmad and Al-Tabrani as a sound hadeeth)
Abu Hurairah narrated that the Messenger of Allah (saws) said: “In the end of time there shall come men who will swindle the world (in Arabic Dunya comprehensively intending the entire globe) with religion (Deen), deceiving the people in soft skins of sheep, their tongues are sweeter than sugar and their hearts are the hearts of wolves. Allah [Mighty and Sublime is He] says: ‘Is it me you try to delude or is it against me whom you conspire? By Me, I swear to send upon these people, among them, a Fitnah that leaves them utterly devoid of reason.”) Tirmidhi: Vol. 4, Book 10, Hadith 2404)
It is clear from the above narrations the prophet was referring to different types of liars, some in his Ummah some not, some claiming to be prophets while others where calling to a new way of life, the exact same thing as establishing a new religion.