compared to the Indominus Rex the T Rex is huge, even the spinosaurus is smaller than the T Rex. Set the dimensions.
"Spinosaurus was among the largest of all known carnivorous dinosaurs, nearly as large as or even larger than Tyrannosaurus, Giganotosaurus and Carcharodontosaurus. Estimates published in 2005, 2007, and 2008 suggested that it was between 12.6–18 metres (41–59ft) in length and 7 to 20.9 tonnes (7.7 to 23.0 short tons) in weight."compared to the Indominus Rex the T Rex is huge, even the spinosaurus is smaller than the T Rex. Set the dimensions.
I would put it like this:About the T-Rex vs Giga - I'd say it's both the Rex being too big and Giga being too small. The argument that T-Rex shouldn't be shrunk because it should stay larger than Cerato doesn't fly, because the in-game Cerato is massively oversized as well. I'd say shrink both Rex and Cerato.
The topics of Rex and Ceratosaurus sizes can be debated since these appeared in movies and were not always accurately represented in those. But herbivores like Crichtonsaurus don't have good excuses for being as large as they are at the moment.
You can pretty much ignore the in-game weight values (they are pretty random and don't correlate well with the size of the in-game model), but the in-game length and height values are quite believable compared to the models.The stats of Spinosaurus, Giganotosaurus, T-rex:
As you see, Spinosaurus's length is 15m (in fact the length is between 14-16m -> ok), weight should be about 9-14 tonnes
Giganotosaurus is 12m (too small), weight should be about 8-9.5 tonnes
T-rex is 14m (too big), weight should be about 8-10 tonnes