About resources used by global objects vs regular objects

Hello!
I have to start with the elaboration of different levels. My idea is to have many objects created (as a backup) that will be used to build the different levels. Given my performance issues due to resources (images), what are the disadvantages of using many objects and characters as global objects? I understand that all the resources are loaded when entering the APK, which in this aspect I suppose would not affect it.
Is it better to make many global objects to have them and build the different levels or is it better to have the images and build the objects in each scene with the same image? Are the resources used by a global object the same as those used by an object limited to a scene?
Thanks in advance.