I think the faithful forget that, at this point, they've got nothing to lose. They know there's a least one traitor amongst them (because Zack was murdered after they last voted one out), and so they cannot win without finding them.
Evie is the one who really needs to cotton on to this - she knows she's faithful, so who's got suspicion mounting up? who can she gang up on? who's going to vote for who? If she isn't banished herself, who is she gunning for?
The remaining four - Harry and Andrew might go for Evie, just because it's a likely banishment, but they know its not her, and once she's gone there's still known to be a traitor in there. So they'd be wise to go for each other at this point, rather than Evie, because she's still be there to take final flack, rather than either of them.
If the banishments went Andrew/Harry then Evie, would the remaining two faithfuls (Mollie, Jaz) still be suspicious there was another traitor, given Evie was faithful? Or would they say, that's it, game over, and lose? I think, if it were Andrew remaining, they'd have a dilemma because Mollie suspects him, and if it were Harry remaining, because Jaz knows its him. Who would be more persuasive of the other - Mollie being persuaded by Jaz against Harry, or Jaz persuaded by Mollie against Andrew? What if Jaz suspects Andrew, too?
aaaargh!