If I joined this information only based on something simple like the state or county, rather than the specific address for the new attributes would this randomly match the attributes to the address feature class based on the state name making them inaccurate to the address itself?
Hello Chris,
From what you describe, it doesn't sound like this would be an appropriate way to join the table to your feature class. Assuming that each row in your rental and ownership table are specific to a single address (called a "One-to-one relationship"), joining on County or State will produce unexpected, and quite likely inaccurate results.
If your feature class and table have a column like "Address ID" that would likely be the best attribute on which to perform the join.
Warm Regards,
Micah
To add to Michah's comments, remember to that a join is only good for a one to one or MANY to one relationship. Look at your resulting join table; when you join one to many (which is what you've done) each of the addresses will have joined to them the first instance of your join item. Let's say you have 50 addresses with the COUNTY value of Jefferson and 200 instances of owners with the COUNTY value of Jefferson: each of your 50 addresses will have the same owner ( the first instance).
This may be a case for a relationship class or relate: Is it possible that you may have more than one owner for a single address? Just a thought...