Six Degrees of David Tennant
As suggested by itsescapedyourworld
Faster than that, Michael Fassbender AND Dominic West, incidentally, were both in The Devil’s Whore with John Simm. And...
Oh come on you could have skipped West- Fassbender and Everett were both in The Case of the Silk Stocking.
10 actors and TWO writers. If you throw in the writers, there’s practically NO degree of separation.
Also: Michael Fassbender was in X-Men: First Class with James McAvoy. McAvoy was in Starter for 10 with Catherine Tate...
True, I forgot about Carey Mulligan :) *facepalm*
this is the truth.