Hi,
I'm guessing that the solution you're after is not to sort by the test case ID, which would solve the problem in the example you gave.
I think you're asking how to sort test cases by name but have them display in an order or your choosing. In the example you gave, you could prefix the name of the test case to include a number that will successfully sort in the order you want them displayed (when sorted by name):
Video playback (ads) - 1. Pre-Roll
Video playback (ads) - 3. Post-Roll
Video playback (ads) - 2. Mid-Roll
If I've misunderstood please let me know.