Entry into the Saint Herb Garden was just as difficult as getting into any top-tier sect, and one could argue it was even harder for the Saint Herb Garden because of the regulations set by the founder which placed emphasis more on comprehension than talent.
Though the regulations for being a member of the sect were hard, other rules were rather lax such as the sect allowing its members to guide cultivators who were not members of the sect that were interested in learning medical techniques. They were free to guide them however they wanted, with the only restriction being forbidden to share the core arts of the sect, which was a given in any sect.
