I wondered what Adam Smith thought about your statement that the ideal labor force is slavery. So I looked it up.

( Book I chapter 8 of the wealth of nations seemed to have some information that might be pertinent: https://en.wikisource.org/wiki/The_Wealth_of_Nations; Direct link: https://en.wikisource.org/wiki/The_Wealth_of_Nations/Book_I/...) .

At one point he discusses the wages in North America, and how high wages seem to correlate to rapid economic and demographic growth. That does seem to mean he doesn't quite agree with you on what is more efficient.

In other places, Adam Smith seems to think slavery is rather inefficient. One argument he presents is: who do you trust more with the upkeep of a person? * a master who may have many priorities; * or the person themselves, where their upkeep is by necessity their own highest priority?

Skim it for yourself and see what you can find!