So if I'm reading it right:
-Double Tap
--Weaker against talismans too strong to dispel(i.e divine relics or peer weapons),
--Weaker against opponents with superhuman skill that won't give us the double hit(Elves, Slaanesh daemons, etc).
--Stronger against opponents reliant on armor or raw durability(dragons, dwarves, ogres)
-Guard Bypass
--Weaker against opponents relying on armor or raw durability
--Stronger against high skill or speed opponents
-Both
--The meaningful overlap contains Malekith and similar beings, swording better isn't going to matter here.
I think we've had more trouble with super skilled opponents than super tough opponents, since our answer to THAT is to get clear and Dragonflask them.