I'm just gonna chime in with a small comment: What you say is in theory generally accurate... however it's not something that should be taken as a universal rule. I haven't played this game (I haven't played many lately - just no time these days) but he did mention different universes. You proceeded to show a whole mess of examples of characters all within the same universe.
For a good example of contrasting visual styles (Which was obviously intentional) look at who framed roger rabbit. Sometimes there is good reason to present multiple visual styles, as it's directly part of the narrative being presented, and works along side it. (While I am 100% sure there have been plenty of other times it's been done, I can't actually think of any at the moment because my brain decided to go on vacation).
So while in general yea sure you want to present a single visual style, there are absolutely times when it's ok not to, and that's usually when there is a narrative reason why they'd be different, and it serves to enhance that narrative.
Yeah, okay, you've got a point there. Who Framed Rodger Rabbit, Cool World, Space Jam, the live-action Sonic movies... I suppose an argument could be made for the Lego Movies... all feature Real Actors juxtaposed with cartoon characters of one sort or another. The Smash Bros series and Wreck It Ralph feature characters from different video game universes all teaming up or throwing down. Into the Spider-Verse and TMNT Forever even feature various iterations of
the same character done in different art styles teaming up together.
These are exceptions to the rule. And on the surface, it sounds like 3YoV is doing something thematically similar. The problem is,
it's not.
Each of those IPs I listed have one thing in common other than deliberately clashing character-designs: They're all massive, popular franchises that knew they could rely on audiences turning up to see their favorite characters. In that specific situation, drawing NBA players as cartoons for the whole movie would be a mistake. Making Mario and Samus have the same sized heads relative to their bodies would be a horrific distortion of one of the beloved characters. Putting Eastman & Laird Leonardo alongside 80's Leonardo and 90's Leonardo and then riffing about the tonal whiplash is
the whole point.
I'd argue that there was an effort made to establish a unified design language in each of those cases-- you can see it the most clearly in some of the Smash Bros games, where Bayonetta's a little plumper or Mario's overalls actually look like denim. In Rodger Rabbit this took the form of painting the toons such that the would match the lighting of a scene, and practical effects of the toons constantly breaking or knocking over real-world objects. Anything that would ground them in the real world. Cool World might have skimped on this element a bit. (To be honest, I don't really remember much of that movie.) The Marvel VS Capcom games back during the Pixel Art era really emphasized this dedication to a unified aesthetic, painstakingly polishing popular characters into new forms that were a little bit comic book, a little bit anime, and a whole lot of brightly-colored, dramatically-flexing pixel art.
3YoV isn't a huge franchise like those other properties. We aren't already so acclimated to the characters that our attachment to them as icons is enough to override the Uncanny Valley Effect. So it can't as easily afford to do that kind of Hollywood/AAA victory lap. Black Star Games isn't mashing up two IPs and making as few compromises to either source material as possible. They're creating each character brand new, from scratch, and then telling us their names for the first time ever. We need to be able to fall in love with these characters. Maybe it's different for you, but for me, that whole process goes a lot smoother when my brain can relax and settle into a single art style without any body horror surprises.
But there's another elephant in the room, and that's the fact that 3YoV is a Daz Studio game competing in a landscape full of other Daz Studio games. One of the challenges of using these characters is the fact that everybody and their brother has already used them, and 90% of everything is crap. In order to stand out in that field, you have to make your game look as good as you can. I won't say that avoiding the Uncanny Valley Effect by using compatible models is the best way to do this, or even strictly necessary. I
will say that it is the
easiest step to take, provided one takes it early enough in development that re-rendering isn't an issue.
I stand by my previous advice. But I respect your opinion. There are certainly exceptions to the rule, and popular ones, at that. But being an exception to this rule isn't what
made them popular. Rather, they got popular by following this rule, then they could afford to break it.
(I suppose the exceptions to that would be Rodger Rabbit and Cool World, which both introduced us to entire casts of new characters. But Rodger Rabbit benefited from its association with Disney and, to a lesser extent, Warner Bros, with constant background cameos of popular characters, while Cool World benefited less directly from the same connection by reminding everybody that Jessica Rabbit was hot and advertising itself as the cure for blue balls we didn't know we needed. By the time of Wreck-It Ralph, I think Disney/Pixar had had enough time to perfect the formula that they knew the
exact optimal ratio of new-to-classic characters, so it's an exception to the exception to the exception. They also remade all the Didney Princesses in 3D with subtly tweaked head scales so Pochahonas could sit on the same couch with Merida from Brave and it wouldn't look especially werid. In fact, come to think of it...)
BAM. I rest my case.