I would reject that graph as being, frankly, utter nonsense.

Islam does not descend from Nestorianism. The other connections and relationships are equally vacuous. Twelvers, Zaidis and Ismailis are kinds of Shia, not descendant theological groups from the Shia. Sufism is not a branch of Sunnism, it's a practice within Sunnism. The Ahmaddiya movement claims that the Mahdi returned in the 19th century and follow his teachings, I wouldn't put them as either descendants or subsets of mainstream Sunnism.

In other words, sometimes this is showing "descendant" groups as being a subset of a category and other times its showing branches from an original sect. It's not at all clear what it is implying at each level of "descent".

While we can look at ways that Islam borrowed practices or understandings from Nestorian Christianity as opposed to orthodoxy (remember, this is all prior to the great schism) I think that would be a pretty weak argument given that those kind of theological disputes just aren't all that present in Islam, at least until the Asharite/Mutazilite disputes on God's nature centuries after Islam was revealed to Muhammad. Nestorianism seems to have been the most common form of Christianity in Arabia and Muhammad apparently had some encounters with Nestorians. That's about it.

There is a much stronger case, I would argue, for Islam to owe it's orthopraxic basis to Judaism more directly, despite the presence of Jesus and Mary in Islamic belief, rather than through Christianity, but that's a separate issue altogether.