If I was asking for realism I would have asked that the dinosaurs have scales, be rounder and more detailed, have animated tongues and eyes, etc. I was asking for more proper sizing.
I'm about to release a Farm Animal Player-type pack. The models are far from realistic, but I still sized them properly; the pig is smaller than the cow, and the chicken is smaller than the pig, and looks as if it could be picked up in a blocklander's arms.
Anyways, even if you still considered that to be too much realism to go for, then you would still be going against Jurassic Park itself. Even they made the spino larger than the T-rex in the 3rd movie, and they are famous for making a turkey-sized raptor 6-7ft tall.