Hi @Anonymous ,
If you want to use Face api connector directly, then you do not need to connect other data source.
The data that you use Face api to update will be saved in azure face service.
And all the functions that you need about recognizing faces have been supported in Face api. So I quite suggest you try this.
Maybe you want to know how to find the data stored in face service.
Please go to “Portal.azure.com” and login with your ID: https://portal.azure.com/#home
1)Click “Create Resource” and search for “Face”.

2)From the search results, select Face.
3)Click Create.

4)After you create this resource successfully, open your subscription by clicking on it and go to the “Overview” section.
This is the place where you can find your subscription keys and access keys. You will need to send an access key with each API call header for authentication.

Please enter these information when you create connection with Face api:

Here's a doc about the functions of this connector for your reference:
https://docs.microsoft.com/en-us/connectors/faceapi/#create-a-person
What's more, you could also consider using flow to make this, here's a doc about it for your reference:
https://aylwinwong.wordpress.com/2019/09/02/face-recognition-using-azure-face-api-and-dynamics-365-4/
Best regards,