> There are tricks you can do with animation cycles where if all cycles are relatively prime, then the pattern only repeats every few minutes, hours, centuries. It's part of why we have 13 and 17 year cicadas. They align on a frequency of over 2 centuries, and they have near misses (appearing in successive years) around every 50 years
You didn't explain how this observation fit into the rest of your comment, but if you're saying that putting two things on simple cycles is good enough to look acyclic to players, I don't think that's true. If you have an oak tree and a fir tree next to each other, animated in 13 second and 17 second cycles, and it takes four full minutes for the oak+fir system to repeat itself... people will still notice that the oak tree is on a 13 second cycle, and the fir tree is on a 17-second cycle. There's no rule that says you can only consider things in the context of everything else that might happen to be nearby.
You didn't explain how this observation fit into the rest of your comment, but if you're saying that putting two things on simple cycles is good enough to look acyclic to players, I don't think that's true. If you have an oak tree and a fir tree next to each other, animated in 13 second and 17 second cycles, and it takes four full minutes for the oak+fir system to repeat itself... people will still notice that the oak tree is on a 13 second cycle, and the fir tree is on a 17-second cycle. There's no rule that says you can only consider things in the context of everything else that might happen to be nearby.