yes, but that seems awkward. I am an Urdu speaker and we always say: ہم جوان مرد ہیں. And in Hindi it is something like: हम नौजवान हैं। or if you want you can say: हम नौजवान आदमी हैं। But these translations define HOW OLD YOU ARE. To be honest, when I played the Audio: हम छोटे आदमी हैं। He urgently replied: We ain't mean. You see: the word छोटा can mean your AGE, SIZE as well as STATUS, but when we combine it particularly with the word आदमी, it is mostly taken for STATUS( rarely SIZE). But since Duolingo wants us to use it in the sense of MEN being SHORT/SMALL, we must use small( but again: it conveys the sense of low status, but rarely or almost never the sense of small size "particularly with the word MAN".)
--Hope that helps.