andc I am not sure if reinstalling the OS will solve your issue.
I suspect that in your case it is really the display that is making problems. If it would be the driver then Windows would be supposedly different, no?
But I do not want to kill all your hope of course. You could try to install Sierra on an external hard disk and see if it makes a difference. That might be easier than erasing the hard disk and rolling back a TimeMachine backup every time like I did.
At least rolling back to 10.13.4 solved the eye strain issues for me on the 13'' 2015 laptop. It also has the "staingate" issue but after what you guys experienced with the replaced screens I happily refrain from a replacement.
If you have some money to spare you could also try to get a 13'' 2015 from eBay or even better Craigslist (so you can drop by and test the laptop first hand before buying) and sell the other one that is bad.