Bazz B =/= Yama-jii!, it was only because he too can control flames that he managed to divert some of Yamamotos flames and thus barely escape death with AsNodt and Nanana, they were out for a long while despite all this and this was just one attack! Another one like that and he would've joined 'the overkill' long story short Yama-jii only needs 2 flame moves tops to end Bazz B.
OT: I suppose it's 50-50, it comes down to the question 'can Rukia drop the temperature faster than Bazz can raise it?' moving speed Rukia seems faster but Bazz seems physically stronger so...