I don't think having multiple trackless rides really matters -- MMRR and Rise are both trackless but they're not remotely similar attractions. A park could have 6 or 7 trackless rides (or omnimovers, or boat rides, etc.) and that would be fine as long as the content (far more important than the actual ride system) was sufficiently different. There are numerous parks that are almost entirely roller coasters and that's not generally considered a problem.
The Zootopia ride just doesn't look especially good, though. It has a few places where it gets somewhat interesting... and then you go watch a movie.