[Open investigation] Understanding best way to set up joins in to prevent test failures in `iterable__campaigns`

### Is there an existing feature request for this?

- [X] I have searched the existing issues

### Describe the Feature

Our current development data is returning test failures in the `iterable__campaigns` end models because of fan outs due to the way these joins are currently set up.

These campaign ids are recurring campaign ids, which is the grain of `iterable_campaigns`.

Examining those cases, the issue appears to be that for these recurring_campaign_ids, there are multiple campaign_ids associated with them, leading to fan-out in joins in `int_iterable__recurring_campaigns` .

However none of that campaign id data is brought into `iterable_campaigns`, so it leads to a bunch of duplicate rows.

**If you've encountered these test issues as well, we'd love to get input from you about what would be the best way to set up our joins so we can avoid these fan outs!**

### Describe alternatives you've considered

_No response_

### Are you interested in contributing this feature?

- [X] Yes.
- [ ] Yes, but I will need assistance and will schedule time during your [office hours](https://calendly.com/fivetran-solutions-team/fivetran-solutions-team-office-hours) for guidance.
- [ ] No.

### Anything else?

_No response_