Primum, ne quam multitudinem hominum amplius trans Rhenum in Galliam traducas. Does ‘quam multitudinem hominum’ mean ‘such a multitude of men’?
Aliquis, if preceded by ne, becomes quis. Plautus (shoutout to ferriculus from the Amphitruo thread):
Ne quis > miretus quis sim, paucis eloquar
Ne [ali]quam multitudinem. That he should bring not any multidude. So, he should bring no multitude, although I suspect (I’d need context) that it actually means that he should bring no one at all.