My guess would be that Safot is a corruption of the Hebrew word Tsva'ot, which means "armies" or "hosts" and I agree that the reference to Softim is a plural form of Shophet, a judge or consul type magistrate....thus safot softim should/could really be written as "tsva'ot shoftim be Qart Hadasht..." which would mean "the Hosts of the Judges of Carthage." This derived from the very close linguistic relationship between Hebrew and the Carthaginian language.

As an aside...Qarthadasht is a conflation of Qartah Hadasha (again from Hebrew) meaning new land...

Hope that helps...