@@timlemmens1087maybe the doctor instinctively knows that these kind of universe ending temporal chronoclasms are mainly reserved for crossover events, so these three know that they’ve got a quota to fill.
The only Doctor missing for this audio was Christopher Eccleston’s 9 (I think The War Doctor was missing too). But he wasn’t doing Big Finish yet and he doesn’t like multi-Doctor stories. Same thing happened years later with The Union where he was absent even though he was in the previous 60th anniversary audio.
