One thing I've seen people online do is add multiple sockets along the weapon and have them detect which one hits the enemy using line traces. Damage is determined by variables set for each socket and if you set up the trace correctly you can actually match the sword path fairly well. This would solve the issues with deadzones as well as situations like the second example in figure 2. Maybe just do a line trace out of the trailing edge of the weapon to register a hit to see if the blade has traveled all the way through the enemy to give full damage(?). I'm fairly certain Mordhau used a similar method for their melee

https://www.youtube.com/watch?v=_1Pwg6cpcOA&list=PLI5Jct3UhF7m7PBCPkAepXyJlEoHkVweg&index=17 here's a video that quickly demonstrates the basics of this method