The materials of the home’s facade should be considered before painting your home. When painting flat surfaces like siding or wood, you can opt for standard outdoor paint. When painting a textured surface like stucco or brick, “elastomeric” paint is a much better choice. This type of paint can stretch more than normal paint, which allows it to bridge over small gaps and crevices, painting smoothly over texture.
Oh, where to begin? Let me start with 'watered down paint'. 25-50% before the material gets to the site? Impossible. You would basically be painting with water at that point. It would be less of a hassle, and cost, to simply use proper material. You would be forced to apply three coats instead of two, as the coverage would be horrible. Whatever cost you think might be saved in materials would be lost in labor.