@Zimbres, yes 3 should be fine. I believe 4 is also fine, but after that mobile browsers may not render more canvases. IIRC desktop browsers have a slightly higher limit to the number of canvases they will render at once. However, you can get clever and remove canvases that are off screen. For example, that is how our demos page is able to have 11 canvases:
Spine: Demos