The validity of Jurassic Park's dinosaurs

I've been reading the Jurassic Park books and something that bothers me like crazy is how all the scientists keep talking about using the new dinosaurs for studies concerning the actual, extinct dinosaurs from millions of years ago. Kind of like "Oh we don't need to dig up bones anymore because we have the living specimen right in front of us."

 Maybe I'm stupid but considering their DNA has been mangled up with other DNA AND the fact that these animals were created in a controlled environment, I feel like that would instantly invalidate any research they do on their 'natural' behaviour. You could never guarantee that the behaviour they show, the way they interact with each other and their temperament is the same as it was millions of years ago. I feel like you can't even confidently call them dinosaurs in that regard. If they can breed in all-female groups because of the amphibian DNA, who's to say what else has changed??

And considering they're all supposed to be such great scientists, you'd think the topic of their behavioural accuracy would come up more often, no? I'm definitely overthinking this, I know it's just a book/movie but it's driving me up the wall lmao.