Hey there, Peter
How's it going?
If we're comparing guilds/secret societies with religion/temples, then guilds/secret societies are
easier to run. As long as there's enough gold for maintenance they run by themselves. Religions need to preach the word to maintain if not increase worshippers (peasants).
If we're comparing guilds with secret societies then they are alike in every respect except the ones I mentioned & the reasons I gave. I though I could keep identities secret within secret societies but your identity is revealed the moment you send a message.
(probably necessary to maintain hierarchy)