I was not a horse girl, but I was an art kid who learned how to draw horses in a second grade extracurricular art class where we had to actually learn anatomy (i added a horn to mine ofc) (also i used this knowledge to learn how to draw sparklewolves later on, before i discovered MLP)
But! I have drawn a lot of ponies, and I am incapable of sticking to one style for them so in many different styles. I think using real horses (or ponies) is actually really good, because then you're thinking about how to interpret the horse into a simpler style. But they definitely work better if you have a more dynamic post, which I think is why so many pony drawings have that "one leg up" pose. For sculptures I'm sure theres more of a difference in anatomy because I would think that they're manipulating the anatomy so the horse can be posed and stand up.
In terms of finding good references for cartoon art, I think it's also good practice to find the most professional sort of... version of pony that you want to draw and examine that. Like, when I was learning g4 art style I looked at Lauren Faust's sketches on dA, or box art type stuff, instead of the show (cause that show had lotsa weird glitches lmao). I was also really into the babybluebell pony maker on dolldivine and I remember that artist had really great style (It was more like g3, I would say). And things like these g1 stickers I found online were so cute while also having some really subtle creases in the joints that I think give them a great sense of movement and perspective (esp the middle ones):
but I mean, I was never perfect at drawing them, I veered into the territory of stylizing things a lot. I mean, my most recent pony fanart was.... well...
/anyways/ bug eyed ponies aside, it sounds like maybe you just have a more detailed style than other people, which is fine! You could also explore adding shadows to show details around the joints, or even feets that are littler, more like a proper horse. I always really liked pony art where the legs looked more properly little like a pony, like the g1 ponies mostly have legs that seem the same width around, and they really thickened them up by g4, which is just so weird when you look at an actual horse, which have itty bitty legs.