So the main plushie collection says:

Plushie Collection Daydream has 1,579 out of 4689 in this collection!

But I noticed in the high score table that some people have a score of 4690 and was wondering how/why that is.

from what i heard/read there are a couple plushies that have been removed from being counted as a plushie. Why i have no clue. So the total doesn't count those that are removed but it's counted if the user already has it in their collection and thats how they have more than the total listed

Sometimes items are miscategorized when they are released or change categories over the years if something no longer makes sense. If that happens to a collection item, it still is counted for those that did use it that way, but is no longer available for that use. In the case of plushie collections it’s the Plush Balloon that’s no longer categorized as a plushie.

thank you for the answers!

man i was wondering this the other day too! glad to have an answer