How to make Intune MDM policy win over GPO. MDM policy is preferred over GPO’s for the simple reason that GPO require line of sight to a domain controller to apply, while MDM only requires an Internet connection. MDM policy with Intune is also much more reliable, and provides significantly better reporting over GPO.
The big downside used to be that GPO would always win if there was a conflict between a policy from any other source. That is no longer the case, in Windows 10 1803 (and newer builds), Microsoft implemented a custom policy in Intune that we can define to ensure that MDM policy win over GPO whenever there are conflicts. This makes the goal of moving away from GPO to MDM much easier as we no longer have to worry about any potential conflicts from some undocumented and long ago forgotten group policy.