Sanhedrin 50 - Comparisons of Executions' Severity
Stoning is a more severe form of execution than burning, for it is administered to a blasphemer and an idol worshiper. And what is the particular strictness of their transgression? - They attack the fundamentals.
Stoning is more severe than beheading, as can be derived from the law of the subverted city. If most of the residents of a town in the Land of Israel followed the instigation of evil men and worshiped idols, then the residents guilty of idolatry are beheaded, but the subverters themselves are stoned. Since the subverters' transgression is greater, stoning is more severe than beheading.
Perhaps strangulation is just as severe as stoning, since it is administered to one who strikes his father or mother, and the honor of parents is compared to the honor of God? - No, stoning is more severe, since it is applied to an adulterous betrothed girl, whereas for an adultery with a fully married adulterous woman one only receives strangulation.
Art: August Renoir - The Swing