Damage dealt by sweeping attacks is not added to the statistics.

Supposing we have a Smite 5 and Sweeping Edge 3 netherite sword, which is able to deal 20.5 damage per hit to the undead. Then, we use it to hit two full HP (20) zombies at the same time. One is instantly killed, and the other is hit by the sweeping attack, which deals 16.1 damage. Finally, kill the remaining zombie.

If we take a look at the statistics after dealing damage each time, we can find out that the first hit is only considered to be a 20 damage hit, and the other one is 3.9.

It's reasonable that if we instakill a mob, the statistics will only increase by the amount of the mob's HP, regardless of how much damage we deal. However, I think that damage dealt by sweeping attacks should be added to the statistics.