An osf is just all guilds but it's easier to start off as an attack build then convert to a spy build
You can't attack someone with only guilds you can only steal,scout and assassinate, you can also only steal if the defender has money out
Unless you mean you cant attack youre osf then that's because you need to buy spy pots and sell them just before you attack it so you have money to take
If you know an osf that you're osf can hit then ye get the attack building then you osf can hit the other osf and make money so you can upgrade quicker