Sorry for the delay in response. I missed seeing your comment.
Your question is a difficult one for me to answer fully because I don't know ALL the reasons the system was originally setup in the manner that it was. I would need to get the full details from our Partner who made the decision that this was the best setup for our needs.
However, in part , I believe that it had something to do with the way they (our Partner) had setup other systems for users that wanted to combine the use of Sage CRM with an external system called Sage 300 Construction and Real Estate (formerly called Sage Timberline). Integration with Timberline is not something that comes "out of the box". Therefore, they created custom modifications to make Sage CRM "talk" to Timberline. I believe those modifications require the use of the company record.
Another reason I believe that the company record is needed in our design is that each lease could possibly have a "guarantor" or second person associated with it. Therefore, if you look at the company record and click on the people tab, you are most likely going to see two "people" listed there. One is going to be the "resident" and one is going to be the "guarantor" for that resident.
It is confusing. However, it does appear to work with our system. We just have to make sure that we understand how Sage CRM works in the backend to accommodate how we need to customize the system to "talk" to our external system.
That is what I love about the system, we are not limited to "out of the box" functionality. The system appears to be very flexible in allowing the development of the system to meet your needs.
Hope this makes sense. Also, my ears are always open to hearing....but you are not thinking about this and or this! Therefore, I welcome any feedback. Thanks! :-)