Settlers remain during city occupy

I recently needed my settlers to survive. My last village was about to fall.

I Paid For 4 Of them. Was able to get a few tiles away then they vanished. 

That might not be to fair for my attackers.

A possible option could be the refuge unit.

Only build able with one city. And only can buy one. Cheep.

This refuge unit has special excape powers moves 5 tiles through anything Water and enemy units. Refuge unit can found city. 

Also lives through occupation of city.

That's the complex option but surviving settlers would be just as fun.