I think they should start from the human models as the basis at 1:2, not to trash morphological realism or buck any evolutionary rationale behind Halfling's needing larger brain cases or sturdier legs or whatever hehe... Instead I suggest Humans at 1:2 purely for practical workflow type reasons. I think the visuals are way more likely to get fucked up if they are inventing an entirely new skeleton on the fly for their maquette and then trying to fully animate it.
Reproportioning the figures in very nuanced ways might be ideal, but would also probably result in more potential goofs and oversights of the sort we've already seen. Whereas if they could just scale the existing work they've done for humans and create a similar overall effect at half size, I think that'd be passing fair and serviceable for a game like this. I mean clearly they have been having some issues properly animating and scaling the Dwarves and current Halfling models to look decent, doing all the things that the more standardly proportioned humanoids can do.
I'm guessing that whatever tools they are using to model and animate in BG3 have a built-in standard Human frame, but probably not a standard Dwarf frame, which is why the animations look all out of whack right now. They're having to push and pull or distort and invent stuff to close the emotive gaps, in an scheme designed principally for animating normally proportioned Human figures.
If they could just focus on getting an animated Human model to scale at 1:2 then I think they'd at least be halfway to a pretty damn good looking Halfling. Just enlarging the skulls from there to like 1:7 would be somewhat simpler than if they are changing the length of all the limbs and the proportions of the extremities. If they need to rekey all the animations for everything, they'll probably screw something up again, like swords clipping through the figure and spider fingers etc. What they're probably doing right now, if at all, is trying to fix the animations for all the current Halflings models we don't like lol. They should shift that work to the Dwarf model set I think, make sure they look good there, so they can do the same thing rescaling Dwarves to create the Gnomes. Just seems like it would be simpler that way, with fewer potential screw ups in the animation.
With a couple more general phenotypes added to make slim or broader boned and more full bodied figures across the board, then rolling with a more portly Halfling could be a choice rather than a requirement in Char creation. A choice to have a particularly large head or large gut or a hairy set of flapper feet would be a nice touch for the traditionalists, but it should be a different field. The way beards are handled say.
Again though I'd just caution against defaulting to skulls that are notably large relative to the rest of the figure. I think Niara's models look pretty great, but the bobble head effect can easily undermine the potential aesthetic appeal if it takes over. Larian has already demonstrated an aptitude for going way overboard in the wrong direction with it in the current models, so I'd ere on the side of restraint there. Testy's quick edit I think has a very clear read, and could easily be dressed up to my satisfaction.
I'm not at all convinced they'll do anything with this feedback, but I wish they'd revisit the Halfling models from the ground up. Let the Dwarves be dwarfs, but have the Halflings be something else. Right now the Halflings look way too much like Dwarves. Maybe because Divinity didn't have any Halflings? so that was just their go-to modelling as a stopgap? But it just looks off to me.
