[Samba] Joining member server

[Gregory Sloop]

I have three DC's - one running Louis's packages (4.15.3 on Ubuntu 20.04) and two others on 18.04 running the distro packages (4.7.6).
 
I'm joining a member file server running Louis' packages 4.15.3 - and want to make sure that joining using samba-tool is fine.
Recap: 2 or the 3 DC are running a mixture of 4.7.6 and 4.15.0+, but the file server being joined as a member is running > 4.15.0.
 
I assume it's ok since the machine running samba-tool is >4.15, but I also don't want to whack my AD back-end etc.
 
TIA
-Greg