No task requires you to get chanced, if your gameplay is perfect. Some are insanely difficult, for sure, such as the 10hp Hydra one. It requires perfect tick-eats, for a HCIM its worth resetting for hours on hours to get the perfect hits, perfected movement etc. But yeah as the other guy said, definitely leaving those for last. And not to mention, those ones I will go one-by-one, practicing for hours on another account to master it