The majority of tutorials will guide you through the techniques required to do the 'merge', very few will tell you what you should be aiming for.
Hey this is all rule of thumb and you are taking it too scientifically for my liking, photography is one of the arts in my opinion and it may be about capturing moments in time and conveying those to your audience, but you do that in whatever manor you require. If you think it looks better with the sky and foreground exposed exactly the same then you have done your bit correctly...there should be no absolutes in photography otherwise all our pictures would look the same
