It's not that hard, it's just like Dark Souls, you have to learn how to bullshit your way through the task in front of you (I don't talk harmful exploits here). Just learn how to aggro a single npc out of a pack and so on (<- is pretty fun actually) and a little hint: use LW, esp long-ranged ones, you'll feel like you are using sneak-throw build, npcs will just shout "where is he?!" And wither away the next second (m4 2 shots npcs on S rank missions, 3-4 shots on SSS, in the eye obv.)