So with thermals, they don't have conventional optical zoom like a day scope, they use digital zoom. The more you zoom, the more pixelated the image gets, getting worse and worse. That happens pretty dang fast, on a 640 resolution it degrades drastically after 2x, on a 384 it's drastically every time you push the zoom button. The reason higher resolution looks better is because it has many times more pixels to zoom in on, easiest way to think of it is the higher resolution means higher detail.
When it comes to base mag, most thermals made range between 2x and 4.5x (a few are a littlemore or less), that's the bulk of the market. There is a pretty drastic difference between say a 2x versus 3.5x base mag. 2x and under has a wider FOV but 16x on the top end. If you have a 3x scope you have usually 24x on the top end but still have a smaller FOV.
Most coyote hunters that hunt the typical open terrain needs the magnification to make longer shots and to see coyotes at greater distance. The 3x - 4.5x is the best choice. For hog or coyote hunters that shoot at close distance because of tight terrain need a giant FOV and that's where the 2x base mag shines.
One thing to remember is marketing shenanigans. Anytime a new "best" thermal hits the market, you'll see videos from it almost exclusively at base mag, shooting animals at close range. That's marketing bullshit because EVERY single thermal degrades with zoom. 18k Iray, 12k Eotech, 10k Nvision, 10k Trijicon, 8k Pulsar, ALL OF THEM look like shit at maximum magnification. The flip side is in good thermal conditions, they all look pretty decent at base mag so point being, don't go by video footage alone to make a purchasing decision.