I knew that those trees could be problematic or misunderstood, with this wave in concrete I was looking for recreating the experience of running through the woods. Maybe another kind of trees could be more effective, and less confusing. Thanks.
Yes, the objects are spawned in a grid!! I've built a wave generator and what you are seeing here is a row of 5 spawners seeding 1 tree per row in a sinusoidal triangular shape, same for coins, but in a reversal sinusoidal triangular shape.