Trying to build naturally spawning structures bigger than 48x48x48 with jigsaws

Hello, basically, my problem is that i can't find where i'm going wrong in this, im building a huge church, so i need to use different template_pools so i can generate them not randomly, but for some reason it only generates the first one connected to the first part of the structure, i tested and it looks like it needs to be connected to that part idk why. If anyone has experience with that and can give some advice i will thank a lot.