ActionScript 3.0 :: One Large Bitmap, Or A A Few Smaller Ones?

Let's say I have some background made up of 4,000 small vector images (doesn't matter what they are, say flowers or stars or something). Once this background is set, these small items won't move or animate. The background will stay the same.What I would do, rather than keep 4,000 sprites on the stage, I would create one single background "Bitmap" which has all the sprites drawn onto it once.Is this still a good idea if that Bitmap is so large it covers the entire stage (which may be quite large for larger monitors if using NO_SCALE and fullscreen or something), or is it better to break that large Bitmap into 4 or more smaller ones placed seamlessly alongside eachother to seem like a large one?