The difference being that Peja and CWebb played together fantastically. So far Fox seems a bit better without Haliburton, but Haliburton looks like a completely different player when he's the lead ballhandler/playmaker and Fox isn't playing.
They certainly could figure it out, but both are better with the ball in their hands - Fox because he's not an off-ball scorer and Tyrese because he controls the game to a much greater degree when running the offense.