The most basic fact is that you can't judge a fighter until he faces his biggest challenges, and that is why Froch is ranked above Bika. Bika has faced those challenges and lost, Froch is yet to.

It doesn't mean that Froch will achieve any more than Bika, but I think that Froch has more chance against Bute that Bika would in a rematch, and would also have more chance against Kessler, though I believe they'd both lose.