What is the primary difference between the approaches used by Christopher Leslie

What is the primary difference between the approaches used by Christopher Leslie Brown and Chernoh M. Sesay, Jr., and how does their approach affect the arguments they make?
Only use these two books for sources:
Brown, C. L. (2013). The Problems of Slavery. In J. Kamensky & E. G. Gray (Eds.), The Oxford Handbook of the American Revolution (pp. 427-446). New York: Oxford University Press. 2013), 427-446.
Sesay, C. M., Jr. (2014). The Revolutionary Black Roots of Slavery’s Abolition in Massachusetts. The New England Quarterly, 87(1), 99-131.