Upgrading Fortigate through FortiManager with different ADOM versions.

I run FortiManager 7.2.8.

2 Adoms are referenced : the root  for firmware version 7.0 abnd an other one for firmware version 7.2.

ADOM 7.2 groups devices running 6 Fortigate 7.2.x devices.

I have 2 Fortigate 200F running 7.0.14 version and I would like to upgrade these 2 devices in 7.2.x version. (It's the first time I have to upgrade using ADOMs).

Can you tell me what are the best practices about running this upgrade ?

Do I need to move the 7.0 device to ADOM 7.2 and then upgrade the devices ?