+1 for everything in this thread. For those saying they shouldn't look like skinny children: they should look like you took an adult human and scaled it down equally in all directions, not a child. Like what happens with regular everyday humans... a 4'8" gymnast doesn't look you took a 6'8 basketball player and squished them down weirdly in one direction only.
NwN2 did a decent job of it.
NwN2 is based on 3.5, in 3.5 halflings had a triangle head/football head. I don't remember if they actually did that for them or not, been to long. If I remember correctly both types of halfings (longfoot and strongheart) were proportioned different, first was thinner second was stocky. An ya, this guy is right on them being exactly human proportioned but shrunk down in size at least in 3.5. Presuming its the same in the other editions but I don't have the material in 5e and it would require some reading for 4e. I did play pathfinder kingmaker a while back and they had oval shaped wide faces with big furry feet.
Btw the original post with the first pick was from 3.0 or 3.5, its pretty old art, kind of shocked they are still rocking that in 5e.
Like I said previously resources are probably better spent else ware since right now halfling models are fine, animations do need work. If anything I would recommend rethinking on how gnomes look, if you haven't already check out the mod from nexus on gnomes. Doesn't look to good.