It sounds like you are being constrained by fill rate, but as I noted in my first reply this is not something I would expect on such hardware, or at least I would expect you to encounter other problems first. Just drawing a few hundred sprites, e.g.textured rectangles, should not be expensive. Each has only four vertices and two triangles which should not stress Starling.
There are a couple of things that could cause it to be fill rate limited. One is if the sprites are quite large, taking up a lot of screen area, so they overlap and areas of screen can be drawn over many times. Especially if the textures include alpha. To deal with this you can pre-compose textures, such as backgrounds which tend to be large and static, drawing them into a RenderTexture which then is drawn behind everything else. Also draw anything that does not need alpha blending without it, using BLENDMODE_NONE to disable alpha.
The other thing is if your individual pixels are expensive, so if they have effects such as filters applied to them. Again pre-composing effects can help with this, or finding another way to do effects, depending exactly what you are trying to do.