I love the idea of multi-Doctor stories. I think everyone does. The reality of multi-Doctor stories is quite different. Titan Comics recently published a Four Doctors series written by Paul Cornell. Now if Paul Cornell can't pull off a successful multi-Doctor story, no one can. Well, he didn't pull it off (in my opinion). But Cavan Scott & George Mann have. This should be a training manual on how to pull off a multi-Doctor story.
Basically, it's a 12th Doctor story, but it also stars 9, 10 and 11 with their respective companions. In a nutshell, the Cybermen hook up with Rassilon, thereby giving the Cybermen access to time travel and all hell starts to break loose. None of the Doctors leave their respective timelines and meet up, but instead they each have to deal with the fall-out of the Cybermen disruption of time and reality.
This was such a well done story. I'd love to see another multi-Doctor story done in this style, maybe featuring some of the earlier Doctors, or a mix of old and new.
Doctor Who: Supremacy Of The Cybermen
Writer: Cavan Scott, George Mann
Artist: Ivan Rodriguez, Walter Geovanni, Alessandro Vitti, Tazio Bettin