This should be critting every hit. Zealot crit with scourge and fury (30 + 25 + 5) + knife with riposte and crit perk (15 + 20 + 5) = 100
If crit isn’t additive, then it needs to be explicitly stated within the game, with a live calculator showing the real bonuses you’re getting (same for damage reduction or any other bonus, really).
Also, if crit isn’t additive, then it should be. Change your numbers around if you don’t want 100% to happen.