I think hop oil content is a good way to ballpark how much hop flavor/aroma a particular variety will give compared to another. I haven't seen a linear increase in flavor, however, when trying to adjust hop quantities in a recipe, so there is definitely a lot of trial and error.
One example is Motueka. I love the flavor and aroma of this hop, but the oil content is fairly low (0.8 mL/100g). But you can't simply use 3 times as much to get it to hold its own in a blend with something like Citra or Nelson (trust me - I've tried).
The thing is, there are multiple hop oils in each variety, and each one has different flavor thresholds. As you increase the amount of the hop used, you are also potentially changing the flavor profile.
Having said all that, oil content is a good way to ballpark a recipe as a starting point.