Is there any rule of thumb for determining battery quality between laptops or laptop brands?
(With that I basically mean how rapidly they degrade. Not to be confused with capacity which can be found in spec sheets.)
One thing I noticed is that my Surface Go battery is much more stable than my Acer Travelmate. Are HP and Dell businesslaptop batteries also better? What about something like HP Spectre vs HP Elitebook?
Yes. The Go batteries hold up quite well. My Go2 battery retains 92% of its original design capacity, more than 2.3 years from the time I purcahsed it (24757 Mwh). I do not baby my devices.
I don’t know if there’s a rule but I’ve had three different Latitudes assigned to me at work that ended up having batteries that got swollen and started to warp the chassis, so that doesn’t seem good on their part. Either that or I’m cursed. 
Thanks for confirming, do you know / guess the same would be for other new Surface devices like Surface Pro 8 or Laptop Studio?
That is spicy pillow material right there 
( Reddit - Dive into anything ). That does surprise me since Latitude tend to be reliable otherwise, do you think it got too hot? (I know excessive heat can damage batteries and business laptops sometimes lack good cooling solutions)
It might have been heat-related, but also could have been the lower to mid-end models that my company was buying. Probably both.