The only thing you see from that Gemara is that the Rabbanan don’t need physical protection since their Torah protects them. It seems that the Torah does not protect anyone else. And it also seems that the Rabbanan would be protected even if no physical measures were taken, for otherwise
???? ?? ????? ??????? would not really be true. (Perhaps one could argue that they don’t need protection, but they do need there to be a physical protection in order for their Torah protection not to be miraculous, but then in essence they need the physical protection just as much as the rest of the city, albeit for a different reason.) A possible ramification would be that the Rabbanan should not be allowed to use any of the physical resources.