"We would like two bowls of beef noodles."
Only using 想 is not natural since it also means to think as if you're thinking about the bowls of noodles.
But then why are there so many sentences in this course that use 想 without 要? Is there no such ambiguity in those cases? Is what you describe a fixed rule?
I'm assuming maybe it's like when an English speaker is ordering drinks at a restaurant and says "Give us five waters" instead of "Give us five glasses of water". The former is more casual, but the latter is technically more grammatically correct.
Because Duolingo’s Mandarin course was done by an English speaker who studied Mandarin in college
I need to check my typing. I typed 'rao' instead of 'ruo'. I tend to hit enter before checking my spelling.