If you just put the lines higher + lower for the top and bottom parts of the torso clothing and add two 0 thickness segments against the edges of the two higher + lower lines then use a Polyfill to connect them all, it should move fine and provide no issues. If you move it too much of course it will look weird again.
This is why using 3 torso pieces and lengthening them to the right amount is important. Not to mention being realistic with the amount of bend the torsos can have.
If you just put the lines higher + lower for the top and bottom parts of the torso clothing and add two 0 thickness segments against the edges of the two higher + lower lines then use a Polyfill to connect them all, it should move fine and provide no issues. If you move it too much of course it will look weird again.
This is why using 3 torso pieces and lengthening them to the right amount is important. Not to mention being realistic with the amount of bend the torsos can have.
What About The Limbs?
If you want lines on the clothing there, just do the same.