Can it also be translated as "how many people"?
Not that I've ever seen.
In the singular it can mean "mankind", but this plural is certainly "men".
I believe you would want to say "cuánta gente" or " cuántas personas" for "how many people"
This voice says Cuantos sombres and it's look like an advert.
It can't be like that, you might hear cuanto sombres and actually it's exactly how it sounds. Last s sound links to the next word , starting with vowel sound o (for h is mute).
Due to linking when speaking and the h is silent i think that might be it
Why couldn't this also translate to the more commonly used, "How many men are there?"
I put 'cuanto sombres' and it passed it!
how many men is exactly what I said and it counted it wrong