Different constraints need different systems
Droppers, processors, batteries, refineries, storage, repairs, and selling belong to one connected oil line. Calling one family S tier without current costs and rates can push a player to increase extraction while oil is already waiting, or buy capacity while finished barrels are stuck at the sale step.
A useful ranking would need transparent criteria, comparable levels, a repeatable current-build test, and evidence that the same choice remains best across early progression, area gates, permit challenges, and rebirth preparation. Those inputs are not available now.