According to the Grand Champions ID Site at http://www.angelfire.com/on/raventyde/grandchampion.html , Jumpy was released in 2006. He was not pictured with a family, but rather as a solo horse in a group including Amady and Sunny.
It wasn't until years later that I came across an identical mare and foal for sale on eBay, with no names, but with Holsteiner mentioned on the front of the box, similar to Jumpy's.
Shadow, on the other hand, came in the next year, 2007, in a completely different colored box.
Getting them NIB makes it easy to ID who's who. Even if they are out of box but still come with their original tack, it's a safe bet you're getting the assumed horse. But sometimes they are 'naked', and then what can you do? Shadow was sold for quite a bit longer than Jumpy was and is much more common. That means, in retrospect, that Jumpy is more rare, and possibly worth more. But how to tell who you're buying?
Unfortunately, there's not an easy answer. I checked on their legs, and they were both stamped with the same info, and no year. Telling them apart comes down to marking detail and amount of shading, both of which can be too subtle to tell.
Now, on to the comparison pictures.
I also feel like Jumpy's hair is noticeably longer. It feels more bouncy, and sits lower on his neck.
I hope this helps anyone, but please keep in mind these are only two models. Other Jumpys and Shadows may and probably will look different than mine, even the shading.