The only way to know is to test them. I test cameras in my back yard. I set one camera directly above the other, pointed at exactly the same angle, and then walk in front of them at a quick pace from both directions, and then compare the results. Some cameras are so slow I'm out of the frame before the first picture is taken. Some are so fast they get me entering the frame and several times before I leave the frame.
The problem is every camera-maker updates/changes their cameras every year. I've seen a top-notch brand produce a real stinker in a given production year. And I've seen brands that have produced nothing but junk for years suddenly produce a crazy-good camera. Browning comes to mind. Their first several models were junk. Now they produce the best cams on the market. WGI and Moultrie are other examples. One model will be really good, the next, garbage.