Probably one of the bigger misconceptions I often see thrown around: Split Durability doesn't make much sense, actually. One might see a character get punched with a city level attack and think "ah, but a sword or bullet could easily cut them!" However, weapons are just multipliers of force, and while slashing and piercing attacks are usually better (as they require less effort for results), they're still ultimately relying on force and kinetic energy for results. Granted attacks with swords or guns for example can produce similar levels of force as, say, a sledgehammer, with much less effort, but again, it's still force. So that example of a dude taking a city level punch? Bullets and knives aren't doing anything to him unless said weapons have city level feats or scale to said feats.