Quote Originally Posted by sapi
- There is a bug with ballista and cannon towers that can cause them not to work at all, and huge cities get them by default (and lose them if you actually build them)

- No info on targeting priorities, sorry

- No, it'd defeat the purpose of cannon/ballista towers

- Agreed

Finally, welcome to the org
A user-created mod has been created to fix the towers issue. Ask about it in the mod section here or at twcenter.net