1. Whitebeard was sick, and was near-death, not to mention a cannon blowing a hole through his chest is a CLEAR outlier, horrible comparison, and not to mention he clearly wasn't even trying to dodge the canons, bullets, or sword slashes despite taking 267 sword wounds, 152 bullets, and 46 cannonballs. Regardless, he wasn't even trying to, and it going through his chest is an outlier. Using your logic, whitebeard wouldn't even have country level durability then. I can also argue that he was impaled twice by akainu's magma which is 6-B, and neg's dura to an extent, but half the time he was punching it away as well.
2. Even weaker characters wouldn't be damaged, Which explains why it's a literal outlier lmfao.
You clearly don't know what you're talking about if you're going to use the bullets argument.