Take control over Windows Time Syncronisation

I have a domain, MYDOMAIN.
It has a domain controller, MYDC. (Win 2012)
MYDC does not have an external clock and it's ok if it's 5 minutes off.

Then we have member computers - COMPUTER1, COMPUTER2, COMPUTER3. (Win 2012 / Win 7)
It's a small domain. Only one forest.

What I want is that the member computers are gonna have the same time as MYDC.
They have "Type"=NT5DS. (domain sync)

It kind of works, but not reliably.

Furthermore, I want to be able to manually adjust the clock on the DC, and the member computers are then going to adjust within a time limit (say 20 min).

The problem is that they behave differently - despite having the same settings for W32Time as far as I can see.

I want to have control over the parameters so that you can say that if the DC time is adjusted this way and the time difference is x - then that will happen within y minutes.

A readable article on the subject is this:
https://nchrissos.wordpress.com/2013/04/26/configuring-time-on-windows-2008-r2-servers/

Parameters on DC?

Parameters on member computer?

Is it possible?

Possible to use Group Policy?

Local Policy?

Edit registry settings directly?