Yes, of the game. Gladiator crucible balance is a very delicate affair for builds like this one, which is a dw medium armor set with much lower flat damage reduction sources relative to other builds. It relies on % defences, dodge, fumble and phys res + the life steal sustain. Killing slower means more hits connecting and when those are from Nemesis the danger is especially high.
The issue is % defence vs flat absorb. The former dies very easily when swarmed hard boss/Nem but the latter has the potential to not care at all because damage can be reduced to 0. Then add to this the existence of total res reduction debuff which harms %defence a hell of a lot more than flat asborb tanky characters (because 0x1.4 is still 0).
Realistically there is only so much more armor/defence a character like this can get to survive and to push success to 100% without the heavy cost of less damage. Maybe it is not possible to clear in 12 minute or below and hence dead in FG but I know it is not as simple as 30% slower because 30% less damage.