You’re right. The 30 founder women is easily seen in a group of 30 families. Have 30 mothers and 2-3 daughters + husbands and sons for a group of 200. Then you realize some women had only sons or daughters but only grandsons and the number doubles to 500.
A single ship of 500 people could have done it, but they’d have had more than 30 women.
Exactly. The “30 women” are those whose DNA lines continued to the present.