Which is VERY medievally correct. Religions should be heavily advantaged (or have the possibility of a heavy advantage) in the financial markets, if we want to be even remotely Medieval.
Galvez' point is correct. Taxing guildhouses makes running mass money transfers easier. My character in Terran has hundreds of gold in surplus with every guild he is in (which is quite a few). Why? Because he taxes their treasuries, then replenishes them. As such, those guilds never actually gain much and never have a large sum of money on hand, but Hireshmont racks up surpluses he can use to shift around moneys however he wants. And I do this very aggressively, allowing me to move money very easily.
The zero-tax on temples means the only way for me to get a big surplus for religions is to actually give them cash they get to keep. Meaning I can never get net positive transactions (except for monthly account balance changes, but those are practically meaningless in most cases). Taxing temples will simultaneously raise major new overhead, decrease the possibility of large religions and temples prospering, and make financial tricks much easier for clever lords.
I'm not 100% sure about this, but I would suspect that using taxes in order to establish a giant surplus with the guild/religion in this way is unintended. Just a personal opinion but I would think it is close to violating this
"No powergaming. If the only reason you do something is game-mechanics, you should probably not do it. No declarations of war if you don't actually intend to fight, for example. No "assassinate me so the bounty stays within our realm", etc."
