One big difference is whether the branch or schism is still around to argue their point. It is a lot easier to argue that the Ebionites where schismatics because they aren't around to argue otherwise. Second is how many branches there are. Splitting one into two is more likely to be considered a schism than splitting two into three or 112 into 113.
On a personal note, I saw diagram one and thought "That's not right, the Roman Catholic Church should be the trunk with branches coming from it" like diagram 4. The author did a good job of explaining why it wasn't drawn that way.
One big difference is whether the branch or schism is still around to argue their point. Yes, I had exactly the same thought. When its adherents have been exterminated, it's a schism. Until then, it's a branch.