Green Lantern wrote:
That's the whole point, it is meant to be a normal second doctor adventure and also a normal sixth doctor adventure, but the two meet as it turns into the same adventure. Is there anything wrong with that?
...there's the fact that Troughton and Hines being a couple of decades older worked against it feeling like a "normal Second Doctor adventure," as did the anachronistic TARDIS console and the massive continuity glitch of having the Doctor on a mission for the Time Lords.
I think this is the biggest issue with fitting it into the second Doctor's chronology. Jamie didn't learn of the Time Lords until his (and Troughton's) final story, The War Games
, in which they immediately place the Doctor on trial and sentence him to an enforced regeneration and exile on Earth, and return Jamie and Zoe to their own times with their memories of all but their first meetings with the Doctor erased.
Prior to this the Doctor had been on the run from the Time Lords, so there was no point during Troughton's era in which he could have been openly working for them with help from Jamie. This also creates a continuity problem in The Five Doctors
, in which the second Doctor recalls Jamie and Zoe being sent home with their memories erased, so there's precedence. That one could perhaps be explained away at a stretch by the second Doctor having gained some foreknowledge during his mental contact with the third in The Three Doctors