I'm painting the exterior of a building. The surface is stucco. I'm not 100% sure the existing layer is latex paint so just in case I asked my friend to get paint with primer in it. It turns out there's a shortage of paint (or just the tint) in my area so he had to buy it in multiple locations. He got 18 gallons with primer and 6 gallons without it. If I mix it all together in this proportion will I lose the efficacy of the primer or will it be fine?