Board Thread:The Reference Desk/@comment-95.172.232.188-20140404191002/@comment-88790-20140503150142

On another technicality there's also everyone who's in the final scenes in The Five Doctors; Janet Fielding, Mark Strickson, Elisabeth Sladen, Nicholas Courtney all starred alongside albeit briefly Patrick Troughton, Jon Pertwee, Peter Davison and Richard Hurndall.

Anthony Keetch has acted alongside '4 Doctors Davison, Colin Baker, Sylvester McCoy and Paul McGann in various audio stories (though specifically The Sirens of Time and Neverland.

Sean Carlsen has acted alongside Paul McGann (The Natural History of Fear), Peter Davison (The Council of Nicaea]] and Colin Baker (Disassembled).

Actually now that I look at it, it's very easy to find Big Finish actors who've acted with three or even more than that Doctor actors. As Big Finish have some actors who are versatile and can do lots of voices / accents. So it's possible for some actors like John Dorney for example to have acted alongside 5 Doctor actors.