No shit, I already mentioned that. Still more energy than any sword strike can put out. Do you believe his physical strength is on the same level as his ki attacks, which context should tell you, but here is more proof, as if it was needed. A sword strike, an explosion, and a punch are all measured the same way, in joules. Even if the damage they produce is different. But this discussion is irrelevant because we are comparing the swing of a sword to a planet exploding. You do realize the vast difference right? if split durability is true, as you believe, how was Gohan able to destroy a space pod and damage Raditz's body armor, when the former tanked Nappa's country level attack and the former tanked Piccolo's moon busting blast? Are you gonna tell me that space ships and glorified football pads have split durability as well?