You do have a good grasp of proportions of the human figure, and on the simpler poses the static construction makes intuitive sense. They look like people standing comfortably and secure.
The line work on the other hand looks searching and sketchy, a bit trial and error, until one of the lines looks right.
If you want to develop cleaner lines and grow towards a more finished look, you should probably spend time doing some courses on drawing the human form. I think figuring out tricks like working from an anatomical foundation all from just practice and your own invention would be a way longer and harsher path to follow, and with uncertain results.
There are free courses and cheap courses. I can recommend proko.com, even the free version, but it certainly isn't the only available course.
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