I'm giving it 1 out of 10. I got my platinum in roughly 30 hours (it's a fun game, I kept playing after that) and I must say that there are no trophies that require particluar skill or dedication. It just takes some time to earn them, not much time.
Some people may say that King of the Beasts and Familiar Faces missions are hard to get, to that I might say that they are triggered by completing a certain number of missions from "?" employer. There's nothing hard about it, "?" missions are mostly very easy.
Overall, not a singly trophy required me to put any noticeable effort into obtaining it. 1 out of 10 it is.