Game optimized model and textures

Hi everybody! I am from Russia - so i’m sorry for my english.

I am trying to make the open world game, based on real russian city. So it will contain many assets in one time. For optimization i try to do masked textures - dirt and scratches will be realised with black/white mask. Basic textures will be mixed with small tiling samples (max 512x512 pixels). The resolution for mask texture is less is possible - up to 2048 for hard models.
How do you think - it will be more optimized, then draw hard resolution textures for each model?
I’m already tested this method - Unreal Engine 4 Concrete stair / UE4 Бетонирование лестниц - YouTube . Looks not bad i think.

Hi, i am a game developer, but may be i can help you. you can contact me in your convenient time.