Planning with the predecessor of the parent work item

We are using Formal Project Management Process Configuration in our Project Area and using the traditional planning feature.

I have a question about configuring predecessor for a group of work item. When you use MS Project setting predecessor/successor for task groups (which is the parent task of a task) MS Project would consider these relations for the child tasks as well. In RTC this is not the case, RTC ignores any settings of the parent work item. This is mainly the problem when you import a project from MS Project, and the two tools consider these relations differently so the scheduling of the tasks would be different.

So for example let's have the following hierarchy for example:

The only possible way I found to work this around is to set the parent work item to be the Successor of the child work items, but this is a very inconvenient and error prone way to do this. 

So the thing I wanted to ask you if you know anything to do about this or any other possible workaround to do this.

Thanks