I recently asked What limitation is intended by Seeming's "basic arrangement of limbs"?, requesting a rules clarification, and it has been put on-hold for being primarily opinion-based. Frankly I'm not clear on how a request for rules clarification can be opinion-based, thus I'm not sure how I can edit the question to solve the problem. What about the question should I be focusing on fixing, and what's SOP here?
The reason it's opinion-based is that everyone (including you) has the same information to draw on when answering this question. The question could easily be rephrased as "how do I interpret the phrase basic arrangement of limbs". The only way to answer this is to say "here's how I interpret the phrase basic arrangement of limbs", so answers will be everyone posting their own interpretations.
Note that, the answer you got, and which is getting upvoted, is the one that says "actually, it doesn't really matter how you or I interpret the phrase, because the only interpretation that matters is that of the DM running a game". For all practical purposes, it's the right answer, but if the question was reopened, it would probably be swamped by answers saying everything from "humanoids only, duh" to "it obviously lets you disguise yourself as a snake, since they have vestigial legs".