Currently I am not sure how big the scenes are going to be - im trying to research how i am going to handle shadows before deciding haha! But they have potential to be quite long, as the levels are going to be designed missions which will have different environments etc but all from the standard city builder perspective (mine isn't a builder game, but the perspective is the same)
There may be like 20 dynamic objects.
I had thought about doing a big static shadow map, and updating it with dynamic objects, but that seems excessively large as I was hoping to target mobile platforms!
just seems so overkill to have dynamic object shadows, but alas, i cannot think of a better way of doing it
You don't need to update static shadow map with dynamic objects. Just render dynamic object to their own map. And when rendering all objects just sample from both shadow maps. This way you can just use depth textures and hardware PCF.