Best Practice for Salary Structure Setup

Summary: Implementing a new salary structure into Oracle HCM

Content (required): Hi, we are looking to implement a brand new salary structure into Oracle. We plan on having roughly 20 grades and about 7 geo zones. We have employees all over the country like many companies nowadays working remotely pretty much anywhere they want. Should we look to setup 1 salary structure with grades and rates then utilizing the compensation zones and differentials or should we go with 7 grade ladders and then assign a grade ladder depending on the employees location. I am open to either way but hoping for some advice. Keep in mind