Most likely one of them has to go, yes.
IF Harry and Andrew voted the same way and Mollie followed them, they could get rid of Evie first and then Jaz. Then they could vote out Molie, end the game and split the money.
It will make better tele if they realise the only way to win the entire pot is for the other traitor to be banished and turn on each other early on.
Either way traitors win.
Least likely outcome IMHO is that they turn on each other and the faithful don't risk keeping either of them, and banish them one after another whilst still in the majority. V unlikely, because Mollie is not likely to vote against Harry, and Evie and Mollie probably wouldn't believe a suggestion that there are potentially two traitors. Plus if they manage to banish one, they'll be so giddy with excitement they'll lose their brains.