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.
Welcome aboard, Antonalog. Greatest job on your static construction on your figural proportions, indeed. Way to go. But, the line quality seems too searching but sketchiest, to the point where you are trying your hardest to make the forces look too right.
If you are looking to improve your economy of statement thru lines, then I'd like to recommend some freeest courses like Proko.com, Virtual Instructor and more. Oh, and this link here, too, so that you'd get the bestest sense on where and how to handle this exercise.
Let's hope you've found these nicest but most helpful.