Aw, thank you! I'm really pleased it worked even though you weren't necessarily familiar with the characters. :D

Did you do that, here?

Oh, man. That's a surprisingly loaded question - I mean, as a scriptwriter it's fine to do things like that because you've got the actors to pull the character through. Writing fanfic for a fandom as well-established as Who means paying very close attention to the mannerisms adopted by each Doctor - I try to get their voices as different as possible. The similarities emerge despite my best efforts. ;)

This fic, though, takes a bunch of them out of their usual frames of mind: the First Doctor is off-balance because Susan's just left, so he's a bit less irascible; the Third Doctor is off-balance because he's starting to realise that his actions have consequences, so he's a bit less arrogant; and the Seventh Doctor is off-balance because he's underestimated Ace yet again, so he's a bit less manipulative. Putting the stronger personalities on an even keel with the less forceful ones (Five, early Nine) brings the similarities to light.

Or dumb luck. That works, too! :D