Which comes first, Teams or SharePoint?

[JVandy]

If you have an organization with five departments, how should you build your Teams/SharePoint?

Should you make a custom SharePoint site and build or connect a Team (in Teams) to that?

Or Should I introduce the department to Teams and develop the SharePoint site that is auto-created from Teams?

If you already have Teams and have built custom SharePoint sites can you link them without integrations issues? 

[#2]

if you are gonna use Teams, just as well create ( Teams and use the team sites behind these! If you already have team sites you can connect these IF they are modern team sites based on a Office 365 group!

[#3]

It really depends on your business needs in regards of SharePoint use cases. You should ask yourself questions such as:
(1) Is it enough to manage membership of the SharePoint Sites by means of the underlying Group or do I need something much more aligned to the way corporate information should be accessed?
(2) Do I need metadata to classify information stored in SharePoint or is it enough just to store files and structure / classify them by means of folders?
(3) Do I need an Intranet for my organization and a full site not connected to a Group / Team for each Department or Is it right just to use Teams as Collaboration Hub and provide a Team per department?
Think on your business requirements and needs before thinking on how to model them using Microsoft 365 solutions and services.

By the way:
(1) You can add a new Office 365 Group to your existing SharePoint Sites (Groupfy)
(2) Once you have added a Group to a SharePoint Site, you can add a Team (Teamfy)

[#4 · Accepted solution]

This was shared on another thread and I believe it answers my question the best.  Mostly in understanding the governance of teams portion. Thanks @Sudharsan K 

https://office365atwork.com/teams/connect-microsoft-teams-with-sharepoint-site/
https://sharegate.com/blog/microsoft-teams-sharepoint-integration-how-to-adopt-teams-existing-team-s...