It is not easy for me to explain this (because of my english skills), but I believe in this case it was quite simply to understand what i said.
What I would like to say is that it is cumbersome to start a few animations (created in groups) on the main timeline at different times.
If Hype 3 PRO where intelligent i expected, you would only have to move the "groups" on the Main Timeline to different positions. Very easily. Start then and you should see, that the groups start thier animations (or what ever is inside the group) when the play head arrives each group position!
Instead, you have to convert all groups to symbols, or give each group, as you say, an extra timeline.
I've talked about the example video. That would mean everything.
Altogether effort for such a simple thing.
It is a little confusing that this could not be understood. Maybe I need to do a screencast