So, the impression I get is that GeeDubs tried to distance themselves somewhat from the overtly Tolkien influence, even with the grim shading that they'd put on the imagery. Note that elves, dwarves and orcs are more widespread fantasy,: so they remained in the spotlight with a new spin to them, whereas halflings are more associated with Tolkien and Dungeons and Dragons (which never denied it Tolkien influence). 40k dwarfs. Imperium accepted human subtype who are industrious. And technically still around, under a rebranding. Can't recall the name of the new Imperium dwarfs, but they are... I'm pretty sure the Mechanicus have thoughts about them and their tech.*cough*cloning and artificial intelligence*cough*
So a smaller version of Ogres of the Ogre Kingdoms? That's true. I've found next to nothing about them on my Warhammer journey. It's probably something that you have to purposefully seek out.
On the contrary, in Fantasy lore Halflings have been confirmed to be pretty much the same - extreme gluttons that steal, eat, drink and have sex indiscriminately. A suitable injection of grimdark upon Tolkien's more utopian source material. In the Fantasy world they get mashed by a random Orc Waaagh! every so often which is why they officially remain loyal to the Empire's protection. Rather than being ignored, it's simply that most of their lore comes from Warhammer Fantasy Roleplay, where they play quite a lot more of a part, than standard Warhammer Fantasy. A summary of it all can be read here: https://warhammerfantasy.fandom.com/wiki/Halfling Pretty much... as has already been mentioned here it is often believed that the two races were created together in the Old Ones' attempts to try and create a race resistant to Chaos that could still wield magic (unlike Dwarfs). In the case of Halflings this seems to have succeeded, but of course the race is especially physically weak and uninterested in and incapable at warfare, while in the case of the Ogres it failed to a degree (as Ogres that serve Chaos forces often end up mutated, and retain the gluttony of the Halflings as well as being as violent and crude as Orcs).
Dwarfs are resistant to Chaos (but not immune), however only the blessings of Chaos/Hashut allows them to wield magic (though not without consequences!). Curious, in lore, how tall are Halflings in comparison to Dwarfs?
I think... Maybe a head shorter at most, but even if they are of height with a Dawi, their statures make them look smaller. Dawi are built like brickhouses, which gives them a presence that gives a perception of extra height, compared to a halfling, who is built like a Potbellied hungry man.