Thanks for the praise! Shanties are not considered guilds for scoring. Guilds are the tokens that come from the guilds box on your board, and shanties are from your supply
it is, yeah, but in particular, you are incentivised to guard the bell tower quite heavily, and if someone were to come in when you only have 4 guys, it could be quite easy for then to wipe it, even with The Bell Tolls, so they need to balance stacking vs spreading out. Also, their most flexible guild, bailiffs, also place shanties as a penalty