People who fled a famine so severe that it lead over 100% of that country's population to emigrate are surely a representative sample of a normal physique from that era, especially immediately after a week-long ocean crossing.
Of course most eras have famine victims, once-in-a-century famines happen more or less every century after all. But treating those famine victims as representatives of a normal physique for that era would be foolish, in any era.