Should Pentecostals be considered their own branch of Christianity?

[True Federalist (진정한 연방 주의자)]

The idea that all the branches of Christianity should be viewed as having the same branch point is to say the least odd. The first branching is between the Occidental and Oriental Churches. The Occidental branch then splits between the Catholic and Protestant branches. The Protestant branch split initially between the Apostolic, Reformed, and Baptist branches, with Mormonism, Adventism, and Pentecostalism being later developments.

[True Federalist (진정한 연방 주의자)]

Not to mention that some early branches (adoptionism etc) withered. Or were forcebly burnt off.

Which as an adoptionist myself, I think is a shame. Tho even as an adoptionist I'm a bit heretical as I don't think that Christ was adopted, but rather that when Jesus was adopted, he became the incarnation of the already existing Christ the Son.

[True Federalist (진정한 연방 주의자)]

I also love the Quaker->Methodist->Pentecostal genealogy, in which they're all seen as somehow outgrowths of Anglicanism (which, granted, in the case of Methodism is actually true) rather than related to the Radical Reformation in any way.

Pentecostalism came out of the Holiness movement, which itself was largely, but not exclusively an offshoot of Methodism, so it's not entirely weird. It's certainly not as bad as calling Lutheranism a branch of the Reformed church.