All of the ceratopsians in Evolution were scaled up to be the same size as Triceratops for some reason, likely so they could fight the theropods without needing to adjust hitboxes and positionings.
Hope they fix that in the next update comiing with 1993 DLC
Here's something interesting I just found out. The ceratopsians in-game actually have
a couple of varying sizes.
You don't believe me? Ccheck out these pictures with all of the current ceratopsian species in-game on my Nublar experimental map.
Some are similar as the other (but are not all the same together) like for example, the Triceratops to the Pentaceratops and Stegoceratops, or the Nasutoceratops to the Sinoceratops. (Base body height wise)
And the Styracosaurus, I'm not kidding you, is actually a little bit smaller than the Triceratops and other two big ceratopsians in-game already.
Oh, and here's this from community manager Paul_Crowther:
But, if I had to make an exception to that statement, it would
probably be the
Torosaurus that would be eligible for a size change. In-game, it's actually smaller than the Triceratops, as you can see in one of my pictures above. Torosaurus, accordingly to the Dinopedia entry in the InGen Database, says it could be a mature form of the Triceratops. Because of this, maybe it could be increased to be the same size as the Triceratops, as it is equal in height to both the Pentaceratops and Stegoceratops, and is likely the biggest size the ceratopsians in-game can currently get.