Shalom Chaim,

Thank you very much for your interesting question!

First, it is important to note that some Rishonim hold that "Kim Lei bed'Rabah Minei" does not apply to a non-Jew. For example, see Tosfos to Eruvin 62a, and Tosfos ha'Ri mi'Paris to Avodah Zarah 71b.

However, there are Rishonim who wrote that "Kim Lei bed'Rabah Minei" does apply even to a non-Jew, such as Rashi to Avodah Zarah there.

That being said, your question in fact relates more directly to a different principle. This is because "Kim Lei bed'Rabah Minei" typically applies in cases involving two different types of punishment, such as death and monetary payment, but not when the individual is liable for two types of death penalties. Therefore, the other principle is more relevant to your case.

This principle is found in the first chapter of Sanhedrin, where we learn that someone liable for two capital punishments is judged with the more severe one. We do not administer both forms of execution, as was done to Bil'am, because the reason behind this Halachah seems to be rooted in "v'Ahavta l'Re'acha Kamocha." And Bil'am, of course, is excluded from that category.

It may also be that the discussion hinges on what Rashi writes there, from which it appears that the four executions were not necessarily carried out while he was still alive. Rashi writes that after his head was cut off, Sekilah was fulfilled in him. If so, the issue here is not four actual punishments or executions, but rather something symbolic performed upon him or his corpse. Indeed, the Maharsha questions Rashi's words, for according to Rashi there were not four deaths at all, just actions that do not constitute capital punishment.

In any case, according to Rashi's view, your question is certainly less difficult.

Best Regards,

Aharon Steiner