Films like this, which are supposed to be grounded in the real world, work best when there's only one "supernatural" element for lack of a better word. Think of it like Back to the Future. You have a time machine, that's far fetched, but the film sells it because everything else in the movie is grounded pretty well. Now, if you start ADDING to that far fetched element things can get out of control pretty easily.
The original Jurassic Park has one far fetched premise which is that we can clone dinosaurs. Everything else was grounded well. Real vehicles, real environment, plausible enclosures, etc. Start adding more far fetched elements to that and things get weird and less believable. Hamster ball vehicles that don't exist and are completely impractical, raptors trained like guard dogs (not convinced that this is the case yet), and on. The more you add the sillier it gets.
So it's not that one is more far fetched than the other, it's that the combination of them has an accumulative affect.
