once the spending agreement is abolished because everyones fed up off RB blatantly breaking it ferrari , mclaren and mercedes can be top dogs again
They were top dogs because they had money for almost unlimited testing. Besides even without a spending agreement it won't matter to mercedes because they are reportedly not all that interested in spending much more than they get back in installments from mclaren. Plenty of reports suggesting Mercedes are not all that interested in listening to Brawn and suits not all that happy with what they are already spending at the team.
Mercedes will never be a top dog, apart from in the engine supply department.