The duty cycle gets neglected or forgotten but needs to be factored in also when considering winch size. On a given pull,
both winches setup with a snatch block, the larger capacity winch doesn't have to work as hard as the smaller winch. Most folks don't even think about it until they feel the winch on a pull to see how hot it's getting, or the winch thermally shuts down.
For example in the documentation that came with my 2011 Badland 12K winch, there were specs for the 12K, but it also contained specs for their 6K and 9K winches. So let's take a 2k pull as an example, which each winch should be capable of pulling(all specs quoted on 1st layer). The amps a winch is drawing is generally going to give you an idea of the heat generated, or more to the point - the more amps, the more heat. And excessive heat is a big winch killer.
2011 Badland winch specs from owners manual
6K winch draws 135 amps at 2K pull
9K winch draws 132 amps at 2K pull
12K winch draws 115 amps at 2k pull
9K winch draws 280 amps at 8K pull
12K winch draws 242 amps at 8K pull
Other winch brands will have different specs, but I'M confident they'd follow the same pattern. After owning an 80 for over 20 yrs now, I tend to agree with
@jonheld in saying I'd not run with anything less than a 12K on an 80. However, yrs ago, when I first got my 80, I put an 8K Ramsey on my ARB. Thank God I was able to replace it with the 12K that's currently on it. One thing's for sure, I immediately noticed the difference whenever I needed to use it.