There’s now actor 3? I don’t get it.
Could you please explain in a lot of detail what you’re trying to do. Grilling people for info is no fun at all. 
And the bullet points? As explained above - the overlaps happen simultaneously. You need additional data to determine who’d go first. Provide a real life example, include a screenshot, with arrows and stuff.
We may be simply missing the point of what you’re trying to achieve.