Indominus rex and Indoraptor hand thoughts

(Spoilers for Fallen Kingdom, not much for Jurassic World,
and none for JW: Dominion)

As it was recently brought to my attention in a comment to a picture I drew of indoraptorlet Sunny using her opposable thumbs, the movie hybrids' hands are a bit weirder than I'd previously noticed: They seem to have two phalanx bones on both the first and second digit, when I'd assumed it's only the first, and that the second would have more than that like the third and fourth do.

In addition to scrutinizing the movie, here's a screenshot I took of the hands of Jurassic World Evolution's Indominus rex model, which was created using the model from the movie. Yep! Looks like two phalanges on the second digit. Okay, why does that matter?

Dromaeosaurids like Deinonychus (which is what the JP/W Velociraptors were originally based on) had two phalanges on the first digit, and more than two on the second and third digits, as seen in this comparison with an Archaeopteryx forelimb. T. rex also had two phalanges on the first digit, and three on the second. Which kind of means that instead of digits analogous to humans' thumb, index, middle, and ring finger, the JW movie hybrids have two thumbs on each hand + index and middle finger.

As I said in my reply to the comment, out of universe this is probably a result of their hands having been constructed when designing the creatures by indeed just adding a thumb to a complete JP/W Velociraptor hand, even though in my caption to the picture I'd said that this is not the case (because I'd just assumed that at least this part of the designs would follow what's more biologically plausible, lol). For an in-universe explanation, one guess that came to mind is that perhaps something having to do with the many genetic modifications these animals have taken to produce caused a joint in the second digit to fuse in the embryo stage, or just have the second digit underdevelop considering how short it also is. But as I also mentioned, the Indoraptor is weirder still, and may or may not have two-phalanged second digits.

Saying hello to Maisie. Looks like two phalanges on the second digit.

Stabbing Claire with the claw of the second digit (yes, that's a forelimb, it's not the raptor sickle claw). Looks like two phalanges again.

Mills showing Eversoll a fancy computer model of various layers of the Indoraptor's anatomy. Looks like three phalanges on the second digit?

Hello again. :)

The digit held the highest is the second one. Looks like it bends at three places.

Foreshadowing! Again looks like three joints, and three phalanges on the second finger.

So, maybe this is a difference in the Indoraptor's CGI model and animatronic. Seems strange they would differ like this, but Rexy's CGI model in the original Jurassic Park wasn't identical with "Roberta" (her animatronic), either, so these things happen. The Indominus rex was portrayed by CGI throughout her movie appearance, but Fallen Kingdom used practical effects alongside the CGI.

I know the hand reaching out of the cage in the first screenshot is practical effects, because I remember seeing behind the scenes photos of it. The stabbing could also be. The in-universe CGI is of course CGI. I recall seeing a "how it was made" of the scene in Maisie's room, too, and the Indoraptor being CGI in this shot, and I'm pretty sure the breaking the glass shot is, as well. So animatronic has two-phalanged second digit, CGI model has a three-phalanged second digit?

Jurassic World Evolution's Indoraptor model was also created using the movie one, so here's a look at its hands:

It looks to me like there are three phalanges on the second digit, which is also considerably longer than the Indominus rex's.

Assuming the CGI model's design is the more canon one, what would this difference in the two hybrids' anatomy mean? Maybe this trait in the Indominus wasn't how Dr. Wu intended it, and the Indoraptor's forelimb anatomy is a correction? Or maybe it's a side-effect of other changes? The Indoraptor is a clone of the Indominus rex, with more Velociraptor added to the mix, but maybe some other things, too.

There are also differences in the prototype seen in the movie and the Indoraptors in JWE - behavioral ones that may be caused by anatomical ones. Not that they seem anatomically different, but that's the explanation I could think of. It's a fanon answer to a question canon probably didn't even mean to ask, after all.

I know the hybrids being part human isn't canon, but since I like the idea that they are, maybe Indoraptors have more of that, too, compared to Indominus rexes? (And if, like I speculated in the other post linked in the above paragraph, the prototype has more than the JWE individuals do, I do find it funny for Henry Wu to have looked at this critter to which he'd added ~just a pinch more~ human, and to have thought "nope, too much" like a home baker trying to figure out a cake recipe.)