I have own a Pronghorn, I have owned 2 three pc Thunderhorns, and never shot a Stalker.
The first thing I would say is that riser on the Jackal should be way different then that other two. The Jackal has more of a recurve riser than longbow.
The Pronghorn I owned I regret selling. It was a hunters longbow. Stable, rock solid, quiet, accurate and smooth. Wish I had it back.
I had a 1 pc T-horn and when I bought a used 3pc I sold the 1 pc. I still own the 3 pc (10 years later) and two years ago I bought a second 3pc. I decided there was no reason to own two so I sold the newest one. I love my T-horn 3 pc longbow. Its got all the qualities you would want in a r/d longbow.
If you never shot any of these three longbows I would say they are pretty different from each of other. Its hard to compare because of their differences.
I would say the Jackal is more like the RER LX, and the Blacktail 3 pc longbow.