That may or may not help.
Jurassic difficulties (not sure about the others) have only a set of dinosaurs you can choose from. So far, I don't think I've seen any of the previous additions added to them (I could be mistaken).
The only update that I can think of that severely impacted Jurassic difficulty was the change to Germany (removal of lagoons) - and that change made it harder.
For Canada, I can confirm a win is possible without going for the Spinosaurus (it's really expensive). I got to 4.5 with the Giganotosaurus, then the last 0.5 with a herd of Suchomimus.
A large variety of prehistoric reptiles is one of the factors that make Jurassic World Evolution 2 better than Jurassic Park: Operation Genesis and Jurassic World: Evolution 1. I decided to wait for more DLCs for the variety to grow. Each challenge mode regardless of difficulty have a set of prehistoric reptiles for us to choose. For Canada and Southwest USA challenge modes, it is the dinosaur variety.
Ever since I completed the Northwest USA challenge mode in Jurassic difficulty, I find dinosaur cohabitation needs work especially for the Germany challenge mode and the sandbox mode. Otherwise, I will hate my process of getting 5 stars in the Jurassic difficulty Germany challenge mode like in Northwest USA challenge mode.