Fortress war questions

[Cheetos]

so if lets say some stupid guild and another stupid guild goes into a fortress war, can one of their guild's union come to help?
If so, can a guild attack their own union?
Cause if they can then a union is kinda pointless i never understood the point of a union

[XMoshe]

You have to sign up for the fortress war..If you didnt do that you cant join.

And when 2 guilds from the same union does, I thought they couldnt attack eachother. Not sure about that but why would they...there union after all