Theoretical question

I have several dialler attached to different topics that end up on the same agent group.
They arrive at the agent group via a Collector where all inputs are equal.

So If I have say 4 diallers into the Collector, which ones get to the agents first?

I would assume they would cycle around but it seesm to do all the calls from the top dialler first and then work down.

Is there a way to assure a more even distribution? I thought maybe Traps inbetween the Topics and the Collector?

Unless there is a better way to do this!

Cheers