Yea exactly this. That’s why the Siamangs are a little annoying to me (but their calls and brachiation make up for it)At the risk of sounding dumb, I don't really care that some of the designs are substandard. The majority of my fun in the game is in the planning and execution of building the habitats and surrounding zoo. I don't really spend a bunch of time just watching the animals. I'd say that when I do, a much more noticeable issue is their interactions with the environment, most notably the incredibly floaty and awkward looking jumping animation -- particularly when the pathfinding decides an animal needs to jump when in reality it would easily just walk.
I agree that when you properly look at it, the Lion for example is incredibly behind compared to the more recent species, and would expect it to be fixed in a sequel, but it's not a huge priority for me