Quick thought: Rather than 'overcoming fan resistance', why make the 'new' Thief about Garrett to begin with, if you're honestly trying to do something new with an IP whose last installment was /nine/ years ago? Why dredge up fond memories only to hammer them down again?
I think the problem is not so much that Orzari seems content to suckle his own nether regions with every cliche one-liner he delivers--that could be forgiven in the appropriate role--but that was never exactly something 'Garrett' required. It was the player's job to make the Thief bad-ass, while Russell stuck to the shadows calling out the ironic stuff to our nodding approval as we bashed drunk guardsmen and snobby clerics over the head; a scarred, leathery street urchin who happened to nab some magic and stealth tricks from the Druidic Librarian equivalent of the Illuminati, and took to sticking it to Ye Righteous Authority. What caused the series to culminate was the buildup from robbing fellow scoundrels, to getting screwed over, to finding yourself fighting either fanatical madmen with giant steampunk robots, or Pagan Satan.
Moreover, it wouldn't 'hurt' to bring back some of the religious cults, spooky magic, and warring factions that dominated the first three games; you can only do so much to look more like a Dishonored-knock-off what with the witchy old crone, the baldy cabal and the uniform style of the guard NPCs.
This strikes me as one of those brilliant marketing decisions along the lines of "John Romero is About to Make You His *****", that the studio touts until it realizes how deep it's stuck its foot in its mouth.
Tread lightly, Eidos--you've put yourself in a needlessly stupid position, by making Thief too in love with what it 'isn't' anymore, and rubbing it in our faces to boot.