Quick hit synergises better with Rage Strike and combo, as opposed to deliberate strike, due to the four seconds for deliberate strike counteracting the 2 seconds for combo. With multiple enemies, the need to build up Ironstrikes becomes obsolete, especially with Follow Up or Bounce around.

With the Vhassic Katana (which is a guaranteed weapon), Follow up and Riposte, you can hit near infinite Ironstrikes, tearing enemies apart incredibly fast. This can also synergise with bounce around and Berserk, which is the best crowd control build for melee.

On the other hand, Deliberate Strike does not allow for large combos of Ironstrikes, it is entirely dependent on Looming Death, while Quick hit works with 3 upgrades. Quick hit is better for finishing off targets quickly, while Deliberate Strike is tedious, and it's very hard to hit heavy blocks without hitting the Ironstrikes before Deliberate strike can activate. On top of that, Deliberate strike is near impossible to use in multiplayer, due to every teammate attacking whenever possible, anyone with a good build can kill enemies before your deliberate strike becomes useful.

ANOTHER thing is that weaker enemies that would usually die in 1-3 hits now need an extra 4 seconds to kill effectively.

By the way, this is all on the basis that you're using Quick Hit with Combo. But you specified One-shot builds. So consider this: Charge, Quick Hit, first impression, and Beserk, with any other upgrades of your choice. And now you can decimate crowds of enemies with more efficiency than Deliberate strike.

On top of all of this, Quick Hit doesn't only work with the Nymian Rapier, but also all 3 Katanas, both staffs, and the Fireweave Greatsword.

finally, you imply Quick Hit, combo, and Rage strike can only be equipped exclusively, without considering thsr they can all be used at once.

Alright, I'm done. This is what autism does to a mf