Hi Damon,
Agree with Bruno, complete and excellent answer.
Just additional info to you.
If you want to see the data from all of Organization into one Dashboard, you might not use multiple CRM Organization since the data cannot be combined into one dashboard.
And also another consideration, if the users are same, then better not to create multiple different organization since you need to re-do maintain the users + Business Unit + Security Roles + Email etc.
But, if the users are not same it is another consideration, you can split your organization into multiple tenant.
The advantages to use Business Unit, you can just manage in one organization and imagine if you have 100 sub-division, is not best practice to create 100 organizations as well.
CRM supports multi-level Business Unit, which you can manage its security as well.
"Will the Users (parent users) have access to the subdivisions?"
--> If you use multiple organization, then you need to maintain both.
--> If you use parent-child Business Unit system, then you just need to maintain in one organization, give them access, and remember CRM has Parent-Business Unit privilege (the level is one level lower than Organization level in the Security Role - not full green circle color)
And one more thing as your consideration, is the Product.
As I know, the Product Master in CRM is global setting, it is Organization-owner, not user or team, it means you cannot split to different Business Unit can view different Product.
And again, another consideration, the Customer data, it will be easier if you want to have 360 degree of the customer (if the customers and market are similar across organization) by using only 1 organization since you can just maintain in 1 database + you can also share to the users from another sub-division in one database organization.
For the link, Bruno gave you a good example.
Hope this helps!
Thanks.
