He replaced Greek and Persian languages in office work by Arabic as well as started to suppress other religion except Islam. And I thought –would the win of Umayyad determined? I think – no.
By early 684, Marwan was in Syria, either at Palmyra or in the court of Yazid's young son and successor, Mu'awiya II, in Damascus.[3] Mu'awiya II died in 684 and many of the Muslim governors of Syria, including those of Palestine, Homs and Qinnasrin, gave their allegiance to Ibn al-Zubayr, who presided over a rival caliphate based in Mecca.[3] As a result, Marwan "despaired over any future for the Umayyads as rulers" and was prepared to recognize Ibn al-Zubayr's legitimacy.[3] However, he was encouraged by the Umayyad prince and expelled governor of Iraq, Ubayd Allah ibn Ziyad, to volunteer himself as Mu'awiyah II's successor during a summit of loyalist Arab tribes being held in Jabiya.[3]
Moreover, if Ibn-Zubair stays caliph – as far as I understand, he did not have enough power resources and more relied on his moral authority.
In such case it is possible, that Umayhads would rule in Siria and Palestine (and may be – in Egypt and to the West); somebody (for instance Ubayd Allah ibn Ziyad )- in Irak and may be – in Khorasan. And calif in Meссa will be like califs of 10th century - Reigns, but does not rule