Long time professional artist here, and for "some aspects" to be "different" is common in tracing. Tracing is a good tool to learn things like anatomy or understand the form of something you're bad at drawing, and many artists will do it *as practice*, but some will try to use it in their formal works to bandage what they're not comfortable with.
You won't trace the whole thing you're tracing from in its most base form; you will make modifications (sometimes by lasso tool to cut parts and then re-pose the part you cut into a different position, or drawn by the artist themself where they feel confident in drawing), so it's harder to perceive as traced, or you may trace from multiple pieces (called "frankensteining"). Alternatively, the base sketch might be traced over, but the final artwork's lines are drawn to the sketch so it "seems" different enough due to differences in artist style. There's tons of ways to do so, but those ways will typically include some variance.
All this to say, a good artist knows how to do so effectively to minimize risk; think of it like how cheaters in a game are sometimes great players who know how to get away with it.
