While this is not a spoiler, according to the policies, I would not recommend reading this post before listening to Doom Coalition 3.
I don't think such pages are usually created. There are pages for each of the Doctor's incarnations and there are Romana I, Romana II, Romana III. By contrast, the Doctor's antagonists are usually gathered on the same page, as in the Master, the Monk and Rassilon, no matter how many actors portrayed them.
There is a bit of a difference with The Eleven though. He doesn't use the same name throughout his incarnations. In fact, it seems mildly incorrect for me - worse, anachronistic - to link "Octavian" or "The Imposter" in Doom Coalition 3 stories to "The Eleven". "Brother Octavian" is the Eight, not the Eleven. And after he regenerates, he is the Nine, not the Eleven. These are separate characters played by separate actors.
Perhaps, somewhat in favour of the separation is the fact that the Master, the Monk, and Rassilon never really changed their personality much, not like the Doctor. At the same time, the Eight is a cardinal departure from the other Eleven's incarnations, which are also given somewhat different characterisations.
So I'm proposing to make separate pages for the Eight and the Nine, both of whom have appeared individually, and not only in flashbacks or as voices in Eleven's head. If this is too radical a departure from the tradition, I propose to at least make redirects to relevant sections of the page for the Eleven, namely from The Eight to The Eleven#The Eight and from The Nine to The Eleven#The Nine. That way, the linkage would not be wrong.