More impactful and incalculably more evil for sure but I actually don't know if in terms of number of human lifetimes stolen it would be larger. Probably if we count secondary effects caused by the slave trade and ongoing marginalisation though (like if your life falls apart because you got attacked by slavers then the labour you would have done for yourself/your community is stolen in a sense).
Kinda silly and bizarre maths to do anyway. Chattel slavery vvv bad, slavery in general v bad, Looting and enclosing commons also bad. Rich people exploiting others is bad and they should be punished for doing what they knew was wrong.