This strengthens the link between preventing major incidents of fraud and advancing progress in a scientific discipline. Without (A), the argument contains no premise that allows us to conclude that anything is “conducive to progress in physics.”

The premises already establish that “further major incidents” of fraud were prevented in biology after the enhanced safeguards. What’s missing is how this relates to scientific progress in the field.

The physicists never claimed that their peer review system was “completely” effective. We want to establish that improving physics’ safeguards will help advance progress in physics. Showing that the current peer review system isn’t perfect doesn’t help us reach this conclusion.

If anything, this might weaken by pointing out a relevant difference between biology and physics that could suggest what happened in biology after safeguards were established wouldn’t necessarily happen to physics.

If anything, this might weaken by suggesting that stronger safeguards in physics wouldn’t necessarily have a meaningful impact on major incidents of fraud, since there are already so few.