You answered your own question x__x " the only explanation to save them is that those Bijuu bombs weren't like what Obito was using before (the smaller balls) to destroy everyone.". Its not just the only explanation, it is the explanation.
You answered your own question x__x " the only explanation to save them is that those Bijuu bombs weren't like what Obito was using before (the smaller balls) to destroy everyone.". Its not just the only explanation, it is the explanation.