The following excerpts completely contradict the answer from ktunugun, they are taken directly from the 5.0.1 Configuration Guide:
I don't say Kiran is wrong, perhaps it is my version only 5.0.1, or perhaps clarification is needed from someone smarter than me!
Selecting Device Group Precedence
When a device belongs to multiple device groups that have conflicting settings, the device automatically inherits the settings from the device group that was most recently changed.
For a more detailed description of how a device inherits settings when it belongs to multiple device groups, see the “Understanding the Impact of Assigning a Device to Multiple Device Groups” section on page 3-9.
When a configuration conflict occurs, you can edit a device’s configuration on a page-by-page basis and select which device group’s settings should take precedence.
To select the device group precedence, follow these steps:
-Step 1 From the WAAS Central Manager menu, choose Devices > device-name.
The Device Dashboard window appears.
-Step 2 From the menu bar, choose the configuration option that contains the conflicting settings.
A drop-down list appears in the taskbar at the top of the window. This drop-down list allows you to select the device group that you want this configuration window to inherit settings from. The device group that is currently selected is the device group that has precedence.
-Step 3 From the drop-down list, choose the device group that you want this configuration page to inherit settings from, and click Submit.
The configuration window changes to reflect the settings associated with the selected device group.
Understanding the Impact of Assigning a Device to Multiple Device Groups (3-9)
If a device belongs to multiple device groups, a configuration conflict might occur if the groups are not configured exactly the same. In this case, the device will inherit the settings from the device group that was most recently changed.
In some cases, however, a device can retain settings from more than one device group depending on how the changes were implemented.
The following scenario describes how a device can retain settings from multiple device groups:
Action 1: Device A is assigned to Device Group 1 (DG1).
Result: Device A automatically inherits all the configuration settings of DG1.
Action 2: Device A is assigned to Device Group 2 (DG2) so it now belongs to two device groups (DG1 and DG2).
Result: Device A inherits all the settings from DG2, but it remains a member of DG1.
Action 3: The standard time zone setting on DG1 is changed to America New York.
Result: The time zone of Device A changes to America New York, but the device maintains all its other configuration settings from DG2.
In this scenario, Device A’s configuration is a hybrid of DG1 and DG2. If you want to specify which device group settings a device should inherit, you can use the override features described in the “Overriding Group Configuration Settings” section on page 3-7.
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This information therefore implies that, the "our own" group is the one your devices will inherit from, since it was Most recently added to that group.
If you THEN change a setting in the AllWAASGroup, that One settng will take precedence, as it was changed most recently.
This should clarify a lot but the rabbit hole continues for awhile. Download the Config guide if you want to know more!
